Intestinal Proportion of Blautia sp. is Associated with Clinical Stage and Histoprognostic Grade in Patients with Early-Stage Breast Cancer

Polystyrene microplastics disrupted physical barriers, microbiota composition and immune responses in the cecum of developmental Japanese quails

Microplastics, a new type of emerging pollutant, is ubiquitous in terrestrial and water environments. Microplastics have become a growing concern due to their impacts on the environment, animal, and human health. Birds also suffer from microplastics contamination. In this study, we examined the toxic effects of polystyrene microplastics (PS-MPs) exposure on physical barrier, microbial community, and immune function in the cecum of a model bird species-Japanese quail (Coturnix japonica). The one-week-old birds were fed on environmentally relevant concentrations of 20 µg/kg, 400 µg/kg, and 8 mg/kg PS-MPs in the diet for 5 weeks. The results showed that microplastics could cause microstructural damages characterized by lamina propria damage and epithelial cell vacuolation and ultrastructural injuries including microvilli breakage and disarrangement as well as mitochondrial vacuolation in the cecum of quails. In particular, blurry tight junctions, wider desmosomes spacing, and gene expression alteration indicated cecal tight junction malfunction. Moreover, mucous layer breakdown and mucin decrease indicated that chemical barrier was disturbed by PS-MPs. PS-MPs also changed cecal microbial diversity. In addition, structural deformation of cecal tonsils and increasing proinflammatory cytokines suggested cecal immune disorder and inflammation responses by PS-MPs exposure. Our results suggested that microplastics negatively affected digestive system and might pose great health risks to terrestrial birds.

Characteristics of gut microbiota and its correlation with hs-CRP and somatic symptoms in first-episode treatment-naive major depressive disorder

OBJECTIVE

Most patients with major depressive disorder (MDD) have somatic symptoms, but little studies pay attention in the microbial-inflammatory mechanisms of these somatic symptoms. Our study aimed to investigate alterations in gut microbiota and its correlation with inflammatory marker levels and somatic symptoms in first-episode treatment-naive MDD.

METHODS

Subjects contained 160 MDD patients and 101 healthy controls (HCs). MDD patients were divided into MDD with somatic symptoms group (MDDS) and MDD without somatic symptoms group (MDDN) based on Somatic Self-rating Scale (SSS). 16S ribosomal RNA sequencing were performed to analyze the composition of the fecal microbiota. The inflammatory factors were measured using enzyme linked immunosorbent assay (ELISA). Correlation among the altered gut microbiota, inflammatory factor and severity of clinical symptoms were analysized.

RESULTS

Relative to HCs, MDD patients had higher levels of high-sensitivity C-reactive protein (hs-CRP) as well as disordered α-diversity and β-diversity of gut microbiota. Linear discriminant effect size (LEfSe) analysis showed that MDD patients had higher proportions of Bifidobacterium, Blautia, Haemophilus and lower proportions of Bacteroides, Faecalibacterium, Roseburia, Dialister, Sutterella, Parabacteroides, Bordetella, and Phascolarctobacterium from the genus aspect. Furthermore, correlation analysis showed Bacteroides and Roseburia had negative correlations with the hs-CRP, HAMD-24, the total and factor scores of SSS in all participants. Further, compared with MDDN, the Pielous evenness was higher in MDDS. Random Forest (RF) analysis showed 20 most important genera discriminating MDD-S and MDDN, HCs. The ROC analysis showed that the AUC was 0.90 and 0.81 combining these genera respectively.

CONCLUSION

Our study manifested MDD patients showed disordered gut microbiota and elevated hs-CRP levels, and altered gut microbiota was closely associated with hs-CRP, depressive symptoms, and somatic symptoms.

Guideline for designing microbiome studies in neoplastic diseases

Oncobiosis has emerged as a key contributor to the development, and modulator of the treatment efficacy of cancer. Hereby, we review the modalities through which the oncobiome can support the progression of tumors, and the emerging therapeutic opportunities they present. The review highlights the inherent challenges and limitations faced in sampling and accurately characterizing oncobiome. Additionally, the review underscores the critical need for the standardization of microbial analysis techniques and the consistent reporting of microbiome data. We provide a suggested metadata set that should accompany microbiome datasets from oncological settings so that studies remain comparable and decipherable.

Specific microbiome patterns and their association with breast cancer: the intestinal microbiota as a potential biomarker and therapeutic strategy

Breast cancer (BC) is one of the most diagnosed cancers in women. Based on histological characteristics, they are classified as non-invasive, or in situ (tumors located within the milk ducts or milk lobules) and invasive. BC may develop from in situ carcinomas over time. Determining prognosis and predicting response to treatment are essential tools to manage this disease and reduce its incidence and mortality, as well as to promote personalized therapy for patients. However, over half of the cases are not associated with known risk factors. In addition, some patients develop resistance to treatment and relapse. Therefore, it is necessary to identify new biomarkers and treatment strategies that improve existing therapies. In this regard, the role of the microbiome is being researched as it could play a role in carcinogenesis and the efficacy of BC therapies. This review aims to describe specific microbiome patterns associated with BC. For this, a literature search was carried out in PubMed database using the MeSH terms "Breast Neoplasms" and "Gastrointestinal Microbiome", including 29 publications. Most of the studies have focused on characterizing the gut or breast tissue microbiome of the patients. Likewise, studies in animal models and in vitro that investigated the impact of gut microbiota (GM) on BC treatments and the effects of the microbiome on tumor cells were included. Based on the results of the included articles, BC could be associated with an imbalance in the GM. This imbalance varied depending on molecular type, stage and grade of cancer, menopause, menarche, body mass index, and physical activity. However, a specific microbial profile could not be identified as a biomarker. On the other hand, some studies suggest that the GM may influence the efficacy of BC therapies. In addition, some microorganisms and bacterial metabolites could improve the effects of therapies or influence tumor development.

Emergence of rare and low abundant anaerobic gut Firmicutes is associated with a significant downfall of Klebsiella in human colon cancer

Gut bacterial dysbiosis has been linked to several gastrointestinal diseases, including deadly colorectal cancer (CRC), a leading cause of mortality in cancer patients. However, perturbation in gut bacteriome during colon cancer (CC, devoid of colorectal malignancy) remains poorly explored. Here, 16S rRNA gene amplicon sequencing was carried out for fecal DNA samples targeted to hypervariable V3-V4 region by employing MiSeq platform to explore the gut bacterial community shift in CC patients. While alpha diversity indices predicted high species richness and diversity, beta diversity showed marked gut bacterial compositional dissimilarity in CC versus healthy controls (HC, n = 10 each). We observed a significant (p < 0.05, Wilcoxon Rank-Sum test) emergence of low-abundant anaerobic taxa, including Parvimonas and Peptostreptococcus, in addition to Subdoligranulum, Coprococcus, Holdemanella, Solobacterium, Bilophila, Blautia, Dorea, Moryella and several unidentified taxa, mainly affiliated to Firmicutes, in CC patients. In addition, we also traced the emergence of putative probiotic taxon Slackia, belonging to Actinomycetota, in CC patients. The emergence of anaerobic Firmicutes in CC is accompanied by a significant (p < 0.05) decline in the Klebsiella, as determined through linear discriminant analysis effect size (LEfSe) and heat tree analyses. Shifts in core microbiome and variation in network correlation were also witnessed. Taken together, this study highlighted a significant and consistent emergence of rare anaerobic Firmicutes suggesting possible anaerobiosis driving gut microbial community shift, which could be exploited in designing diagnostic and therapeutic tools targeted to CC.

Butyrate inhibits the malignant biological behaviors of breast cancer cells by facilitating cuproptosis-associated gene expression

BACKGROUND

Butyrate is a common short-chain fatty acids (SCFA), and it has been demonstrated to regulate the development of breast cancer (BC), while the underlying mechanism is still unreported.

METHODS

Gas chromatography was used to measure the amounts of SCFA (acetate, propionate, and butyrate) in the feces. Cell viability was measured by the CCK-8 assay. The wound healing assay demonstrated cell migration, and the transwell assay demonstrated cell invasion. The levels of protein and gene were determined by western blot assay and RT-qPCR assay, respectively.

RESULTS

The levels of SCFA were lower in the faecal samples from BC patients compared to control samples. In cellular experiments, butyrate significantly suppressed the cell viability, migration and invasion of T47D in a dose-dependent manner. In animal experiments, butyrate effectively impeded the growth of BC tumors. Toll like receptor 4 (TLR4) was highly expressed in the tumors from BC patients. Butyrate inhibited the expression of TLR4. In addition, butyrate promoted the expression of cuproptosis-related genes including PDXK (pyridoxal kinase) and SLC25A28 (solute carrier family 25 member 28), which was lowly expressed in BC tumors. Importantly, overexpression of TLR4 can reverses the promotion of butyrate to PDXK and SLC25A28 expression and the prevention of butyrate to the malignant biological behaviors of T47D cells.

CONCLUSION

In summary, butyrate inhibits the development of BC by facilitating the expression of PDXK and SLC25A28 through inhibition of TLR4. Our investigation first identified a connection among butyrate, TLR4 and cuproptosis-related genes in BC progression. These findings may provide novel target for the treatment of BC.

Microbiome in cancer: A comparative analysis between humans and dogs

Cancer is a major cause of death in humans and animals worldwide. While cancer survival rates have increased over recent decades, further research to identify risk factors for the onset and progression of disease, and safe and highly efficacious treatments, is needed. Spontaneous tumours in pets represent an excellent model for neoplastic disease in humans. In this regard, dogs are an interesting species, as the divergence between the dog and human genome is low, humans and dogs have important similarities in the development and functioning of the immune system, and both species often share the same physical environment. There is also a higher homology between the canine and human microbiome than murine model. This review aims to describe and organize recently published information on canine microbiome assemblages and their relationship with the onset and progression of colorectal cancer, breast cancer and lymphoma, and to compare this with human disease. In both species, dysbiosis can induce variations in the gut microbiota that strongly influence shifts in status between health and disease. This can produce an inflammatory state, potentially leading to neoplasia, especially in the intestine, thus supporting canine studies in comparative oncology. Intestinal dysbiosis can also alter the efficacy and side effects of cancer treatments. Fewer published studies are available on changes in the relevant microbiomes in canine lymphoma and mammary cancer, and further research in this area could improve our understanding of the role of microbiota in the development of these cancers.

The intratumor microbiome varies by geographical location and anatomical site in head and neck squamous cell carcinoma

Head and Neck Squamous Cell Carcinoma (HNSCC) is a highly heterogeneous cancer that is characterized by distinct phenotypes based on anatomical site and etiological agents. Recently, the intratumor microbiome has been implicated in cancer pathogenesis and progression. Although it is well established that the gut microbiome varies with geographical location and is highly influenced by factors such as diet, environment, and genetics, the intratumor microbiome is not very well characterized. In this review, we aim to characterize the HNSCC intratumor microbiome by geographical location and anatomical site. We conducted a review of primary literature from PubMed and assessed studies based on relevancy and recency. To the best of our knowledge, we are the first to comprehensively examine the tumor microenvironment of HNSCC with respect to these two primary factors on a large scale. Our results suggest that there are unique bacterial and fungal biomarkers for HNSCC for each of the following geographical locations: North America, Asia, Europe, Australia, and Africa. We also identified a panel of microbial biomarkers that are unique to two primary HNSCC anatomic sites, as well as microbial biomarkers associated with various etiological agents of HNSCC. Future study of these microbes may improve HNSCC diagnostic and therapeutic modalities by accounting for differences based on geographic regions and anatomical sites.

A high-fat diet promotes cancer progression by inducing gut microbiota-mediated leucine production and PMN-MDSC differentiation

A high-fat diet (HFD) is a high-risk factor for the malignant progression of cancers through the disruption of the intestinal microbiota. However, the role of the HFD-related gut microbiota in cancer development remains unclear. This study found that obesity and obesity-related gut microbiota were associated with poor prognosis and advanced clinicopathological status in female patients with breast cancer. To investigate the impact of HFD-associated gut microbiota on cancer progression, we established various models, including HFD feeding, fecal microbiota transplantation, antibiotic feeding, and bacterial gavage, in tumor-bearing mice. HFD-related microbiota promotes cancer progression by generating polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). Mechanistically, the HFD microbiota released abundant leucine, which activated the mTORC1 signaling pathway in myeloid progenitors for PMN-MDSC differentiation. Clinically, the elevated leucine level in the peripheral blood induced by the HFD microbiota was correlated with abundant tumoral PMN-MDSC infiltration and poor clinical outcomes in female patients with breast cancer. These findings revealed that the "gut-bone marrow-tumor" axis is involved in HFD-mediated cancer progression and opens a broad avenue for anticancer therapeutic strategies by targeting the aberrant metabolism of the gut microbiota.

Exploring prognostic microbiota markers in patients with endometrial carcinoma: Intratumoral insights

Endometrial cancer, a leading gynecological malignancy, is profoundly influenced by the uterine microbiota, a key factor in disease prognosis and treatment. Our study underscores the distinct microbial compositions in endometrial cancer compared to adjacent non-cancerous tissues, revealing a dominant presence of p_Actinobacteria in cancerous tissues as opposed to p_Firmicutes in surrounding areas. Through comprehensive analysis, we identified 485 unique microorganisms in cancer tissues, 26 of which correlate with patient prognosis. Employing univariate Cox regression and LASSO regression analyses, we devised a microbial risk scoring model, effectively stratifying patients into high and low-risk categories, thereby providing predictive insights into their overall survival. We further developed a nomogram that incorporates the microbial risk score along with age, grade, and clinical stage, significantly enhancing the accuracy of our clinical prediction model for endometrial cancer. Moreover, our study delves into the differential immune landscapes of high-risk and low-risk patients. The low-risk group displayed a higher prevalence of activated B cells and increased T cell co-stimulation, indicative of a robust immune response. Conversely, high-risk patients showed elevated tumor immune dysfunction and exclusion scores, suggesting less favorable outcomes in immunotherapy. Notably, the efficacy of IPS-CTLA4 and PD1/PD-L1/PD-L2 blockers was substantially higher in the low-risk group, pointing to a more responsive immunotherapeutic approach. In summary, our research elucidates the unique microbial patterns in endometrial cancer and adjacent tissues, and establishes both a microbial risk score model and a clinical prediction nomogram. These findings highlight the potential of uterine microbiota as a biomarker for customizing treatment strategies, enabling precise interventions for high-risk patients while preventing overtreatment in low-risk cases. This study emphasizes the microbiota's role in tailoring immunotherapy, offering a novel perspective in the treatment and prognosis of endometrial cancer. Significantly, our study's expansive sample analysis from the TCGA-UCEC cohort, employing linear discriminant analysis effect size methodology, not only validates but also enhances our understanding of the microbiota's role in endometrial cancer, paving the way for novel diagnostic and therapeutic approaches in its management.

Exploring the underlying correlation between microbiota, immune system, hormones, and inflammation with breast cancer and the role of probiotics, prebiotics and postbiotics

According to recent research, bacterial imbalance in the gut microbiota and breast tissue may be linked to breast cancer. It has been discovered that alterations in the makeup and function of different types of bacteria found in the breast and gut may contribute to growth and advancement of breast cancer in several ways. The main role of gut microbiota is to control the metabolism of steroid hormones, such as estrogen, which are important in raising the risk of breast cancer, especially in women going through menopause. On the other hand, because the microbiota can influence mucosal and systemic immune responses, they are linked to the mutual interactions between cancer cells and their local environment in the breast and the gut. In this regard, the current review thoroughly explains the mode of action of probiotics and microbiota to eradicate the malignancy. Furthermore, immunomodulation by microbiota and probiotics is described with pathways of their activity.

Clinical and molecular characteristics of early-onset vs average-onset esophagogastric cancer

BACKGROUND

The rate of esophagogastric cancer is rising among individuals under 50 years of age. It remains unknown whether early-onset esophagogastric cancer represents a unique entity. This study investigated the clinical and molecular characteristics of early-onset and average-onset esophagogastric cancer .

METHODS

We reviewed the Memorial Sloan Kettering Cancer Center gastric, esophageal, and gastroesophageal junction cancer database. Associations between baseline characteristics and tumor and germline molecular alterations were compared between those with early-onset and average-onset esophagogastric cancer using Fisher exact tests and the Benjamini-Hochberg method for multiple-hypothesis correction.

RESULTS

We included 1123 patients with early-onset esophagogastric cancer (n = 219; median age = 43 years [range = 18-49 years]) and average-onset esophagogastric cancer (n = 904; median age = 67 years [range = 50-94 years]) treated between 2005 and 2018. The early-onset group had more women (39% vs 28%, P = .002). Patients with early-onset esophagogastric cancer were more likely to have a gastric primary site (64% vs 44%, P < .0001). The signet ring cell and/or diffuse type was 3 times more common in the early-onset esophagogastric cancer group (31% vs 9%, P < .0001). Early-onsite tumors were more frequently genomically stable (31% vs 18%, P = .0002) and unlikely to be microsatellite instability high (2% vs 7%, P = .003). After restricting to adenocarcinoma and signet ring cell and/or diffuse type carcinomas, we observed no difference in stage (P = .40) or overall survival from stage IV diagnosis (median = 22.7 vs 22.1 months, P = .78).

CONCLUSIONS

Our study supported a preponderance of gastric primary disease sites, signet ring histology, and genomically stable molecular subtypes in early-onset esophagogastric cancer. Our findings highlight the need for further research to define the underlying pathogenesis and strategies for early detection and prevention.

Gut Microbiome of Patients With Breast Cancer in Vietnam

PURPOSE

Gut microbiota play an important role in human health, including cancer. Cancer and its treatment, in turn, may alter the gut microbiome. To understand this complex relationship, we profiled the gut microbiome of 356 Vietnamese patients with breast cancer.

MATERIALS AND METHODS

Stool samples were collected before chemotherapy, with 162 pre- and 194 postsurgery. The gut microbiome was measured by shotgun metagenomic sequencing. Associations of gut microbial diversity, taxa abundance, and gut microbiome health index (GMHI) with sociodemographic, clinical factors, and tumor characteristics were evaluated.

RESULTS

Postsurgery samples were associated with significantly lower α- and β-diversities (P < .001) and showed significant differences in the abundance of 15% of 2,864 investigated taxa (false discovery rate [FDR] <0.1) compared with presurgery samples. An unhealthy gut microbiome was prevalent among patients with breast cancer, with a mean GMHI of -0.79 and -2.81 in pre- and postsurgery stool samples, respectively. In an analysis of 162 presurgery stool samples, diagnosis delay was significantly associated with lower α-diversity, variation in β-diversity, an increased abundance of species Enorma massiliensis, and a decreased abundance of Faecalicoccus pleomorphus. High intake of fiber was significantly associated with lower α-diversity and a higher abundance of species belonging to Bifidobacterium, Prevotella, and Bacteroides gena (FDR < 0.1). We did not find that cancer stage and subtype, menopausal status, comorbidity, antibiotic use during 3 months before stool collection, or physical activity was significantly associated with α- and β-diversities or GMHI although a few significant differences were observed in taxa abundance.

CONCLUSION

Our study revealed that diagnosis delay, high fiber intake, and breast cancer surgery, which is always followed by antibiotic prophylaxis in Vietnam, led to a less diverse and unhealthy gut microbiome among patients with breast cancer.

Breast cancer but not the menopausal status is associated with small changes of the gut microbiota

Background

Possible relationships between gut dysbiosis and breast cancer (BC) development and progression have been previously reported. However, the results of these metagenomics studies are inconsistent. Our study involved 88 patients diagnosed with breast cancer and 86 cancer-free control women. Participants were divided into groups based on their menopausal status. Fecal samples were collected from 47 and 41 pre- and postmenopausal newly diagnosed breast cancer patients and 51 and 35 pre- and postmenopausal controls, respectively. In this study, we performed shotgun metagenomic analyses to compare the gut microbial community between pre- and postmenopausal BC patients and the corresponding controls.

Results

Firstly, we identified 12, 64, 158, and 455 bacterial taxa on the taxonomy level of phyla, families, genera, and species, respectively. Insignificant differences of the Shannon index and β-diversity were found at the genus and species levels between pre- and postmenopausal controls; the differences concerned only the Chao index at the species level. No differences in α-diversity indexes were found between pre- and postmenopausal BC patients, although β-diversity differed these subgroups at the genus and species levels. Consistently, only the abundance of single taxa differed between pre- and postmenopausal controls and cases, while the abundances of 14 and 23 taxa differed or tended to differ between premenopausal cases and controls, and between postmenopausal cases and controls, respectively. There were similar differences in the distribution of enterotypes. Of 460 bacterial MetaCyc pathways discovered, no pathways differentiated pre- and postmenopausal controls or BC patients, while two and one pathways differentiated cases from controls in the pre- and postmenopausal subgroups, respectively.

Conclusion

While our findings did not reveal an association of changes in the overall microbiota composition and selected taxa with the menopausal status in cases and controls, they confirmed differences of the gut microbiota between pre- and postmenopausal BC patients and the corresponding controls. However, these differences were less extensive than those described previously.

Cisplatin and doxorubicin chemotherapy alters gut microbiota in a murine osteosarcoma model

The gut microbiota is closely associated with tumor progression and treatment in a variety of cancers. However, the alteration of the gut microbiota during the progression and chemotherapy of osteosarcoma remains poorly understood. This study aimed to explore the relationship between dysbiosis in the gut microbiota during osteosarcoma growth and chemotherapy treatment. We used BALB/c nude mice to establish osteosarcoma xenograft tumor models and administered cisplatin (CDDP) or doxorubicin (DOX) intraperitonially once every 2 days for a total of 5 times to establish effective chemotherapy models. Fecal samples were collected and processed for 16S rRNA sequencing to analyze the composition of the gut microbiota. We observed that the abundances of Colidextribacter, Lachnospiraceae_NK4A136_group, Lachnospiraceae_UCG-010, Lachnospiraceae_UCG-006, and Lachnoclostridium decreased, and the abundances of Alloprevotella and Enterorhabdus increased in the osteosarcoma mouse model group compared to those in the control group. In addition, genera, such as Lachnoclostridium and Faecalibacterium were more abundant in chemotherapy-treated mice than those in saline-treated mice. Additionally, we observed that alterations in some genera, including Lachnoclostridium and Colidextribacter in the osteosarcoma animal model group returned to normal after CDDP or DOX treatment. Furthermore, the function of the gut microbiota was inferred through PICRUSt2 (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States), which indicated that metabolism-related microbiota was highly enriched and significantly different in each group. These results indicate correlations between dysbiosis of the gut microbiota and osteosarcoma growth and chemotherapy treatment with CDDP or DOX and may provide novel avenues for the development of potential adjuvant therapies.

Microbial Therapy and Breast Cancer Management: Exploring Mechanisms, Clinical Efficacy, and Integration within the One Health Approach

This comprehensive review elucidates the profound relationship between the human microbiome and breast cancer management. Recent findings highlight the significance of microbial alterations in tissue, such as the gut and the breast, and their role in influencing the breast cancer risk, development, progression, and treatment outcomes. We delve into how the gut microbiome can modulate systemic inflammatory responses and estrogen levels, thereby impacting cancer initiation and therapeutic drug efficacy. Furthermore, we explore the unique microbial diversity within breast tissue, indicating potential imbalances brought about by cancer and highlighting specific microbes as promising therapeutic targets. Emphasizing a holistic One Health approach, this review underscores the importance of integrating insights from human, animal, and environmental health to gain a deeper understanding of the complex microbe-cancer interplay. As the field advances, the strategic manipulation of the microbiome and its metabolites presents innovative prospects for the enhancement of cancer diagnostics and therapeutics. However, rigorous clinical trials remain essential to confirm the potential of microbiota-based interventions in breast cancer management.

Sodium alginate combined with oxymatrine ameliorates CCl4-induced chemical hepatic fibrosis in mice

Hepatic fibrosis (HF) is a challenging clinical problem. Both sodium alginate (SA) and oxymatrine (OM) can be used to treat HF; however, the influence of viscosity on the therapeutic efficacy of sodium alginate is currently unknown. This study used a CCl4-induced HF mouse model to screen the specifications and doses of SA and investigate its therapeutic effects on HF in combination with OM. Sodium alginate of different viscosities ameliorated HF in mice, with 232 mPa·s SA delivered at a dose of 100 mg/kg showing remarkable therapeutic effect, characterized by reduced aspartate transaminase/alanine transaminase levels, reduced expression of α-SMA, collagen I, and other related genes, and increased abundance of beneficial intestinal probiotics such as Lactococcus and Blautia. The combination treatment further improved other related indices and increased the abundance of Phascolarctobacterium and Oscillospiraceae. These results suggest that the oral administration of SA may improve HF via the "gut-liver axis" based on the gut microbiota and has potential clinical applications.

Role of the intestinal microbiota and diet in the onset and progression of colorectal and breast cancers and the interconnection between both types of tumours

Colorectal cancer (CRC) is among the leading causes of mortality in adults of both sexes worldwide, while breast cancer (BC) is among the leading causes of death in women. In addition to age, gender, and genetic predisposition, environmental and lifestyle factors exert a strong influence. Global diet, including alcohol consumption, is one of the most important modifiable factors affecting the risk of CRC and BC. Western dietary patterns promoting high intakes of xenobiotics from food processing and ethanol have been associated with increased cancer risk, whereas the Mediterranean diet, generally leading to a higher intake of polyphenols and fibre, has been associated with a protective effect. Gut dysbiosis is a common feature in CRC, where the usual microbiota is progressively replaced by opportunistic pathogens and the gut metabolome is altered. The relationship between microbiota and BC has been less studied. The estrobolome is the collection of genes from intestinal bacteria that can metabolize oestrogens. In a dysbiosis condition, microbial deconjugating enzymes can reactivate conjugated-deactivated oestrogens, increasing the risk of BC. In contrast, intestinal microorganisms can increase the biological activity and bioavailability of dietary phytochemicals through diverse microbial metabolic transformations, potentiating their anticancer activity. Members of the intestinal microbiota can increase the toxicity of xenobiotics through metabolic transformations. However, most of the microorganisms involved in diet-microbiota interactions remain poorly characterized. Here, we provide an overview of the associations between microbiota and diet in BC and CRC, considering the diverse types and heterogeneity of these cancers and their relationship between them and with gut microbiota.

The What and Who of Dietary Lignans in Human Health: Special Attention to Estrogen Effects and Safety Evaluation

Lignans are a group of phenolic compounds found in plant-based diets. The human body can obtain lignans through diet, which are then metabolized into enterolignans. The enterolignans have been linked to several health benefits, including anticancer, anti-inflammatory, antioxidant effects, and estrogen effects. This review explores the relationship between the estrogenic effects of lignans and health. This review not only considers the estrogen-like activity of lignans but also discusses the safe dosage of lignans at different life stages. In addition, this review also identified other types of bioactive compounds that can act synergistically with lignans to promote health. Studies have shown that lignan administration during pregnancy and lactation reduces the risk of breast cancer in offspring. Further studies are needed to investigate the estrogenic safety effects of lignan on pregnant women and children. Whether lignans combine with other nutrients in complex food substrates to produce synergistic effects remains to be investigated. This review provides a basis for future studies on the safe dose of lignan and recommended dietary intake of lignan. We believe that the acquired as discussed here has implications for developing dietary therapies that can promote host nutrition and modulate estrogenic diseases.

Microbial modifications with Lycium barbarum L. oligosaccharides decrease hepatic fibrosis and mitochondrial abnormalities in mice

BACKGROUND

Lycium barbarum L. is a typical Chinese herbal and edible plant and are now consumed globally. Low molecular weight L. barbarum L. oligosaccharides (LBO) exhibit better antioxidant activity and gastrointestinal digestibility in vitro than high molecular weight polysaccharides. However, the LBO on the treatment of liver disease is not studied.

PURPOSE

Modification of the gut microbial ecosystem by LBO is a promising treatment for liver fibrosis.

STUDY DESIGN AND METHODS

Herein, LBO were prepared and characterized. CCl4-treated mice were orally gavaged with LBO and the effects on hepatic fibrosis and mitochondrial abnormalities were evaluated according to relevant indicators (gut microbiota, faecal metabolites, and physiological and biochemical indices).

RESULTS

The results revealed that LBO, a potential prebiotic source, is a pyranose cyclic oligosaccharide possessing α-glycosidic and β-glycosidic bonds. Moreover, LBO supplementation restored the configuration of the bacterial community, enhanced the proliferation of beneficial species in the gastrointestinal tract (e.g., Bacillus, Tyzzerella, Fournierella and Coriobacteriaceae UCG-002), improved microbial metabolic alterations (i.e., carbohydrate metabolism, vitamin metabolism and entero-hepatic circulation), and increased antioxidants, including doxepin, in mice. Finally, LBO administration reduced serum inflammatory cytokine and hepatic hydroxyproline levels, improved intestinal and hepatic mitochondrial functions, and ameliorated mouse liver fibrosis.

CONCLUSION

These findings indicate that LBO can be utilized as a prebiotic and has a remarkable ability to mitigate liver fibrosis.

Microbial endocrinology: the mechanisms by which the microbiota influences host sex steroids

Recent progress in microbial endocrinology has propelled this field from initially providing correlational links to defining the mechanisms by which microbes influence systemic sex hormones. Importantly, the interaction between the gut-resident bacteria and host-secreted hormones has been shown to be critical for host development as well as hormone-mediated disease progression. This review investigates how microbes affect active sex hormone levels, with a focus on gut-associated bacteria hormonal modifications and the resulting host physiological status. Specifically, we focus on the ability of the microbiota to reactivate estrogens and deactivate androgens and thereby influence systemic levels of host hormones in a clinically significant manner.

The tremendous clinical potential of the microbiota in the treatment of breast cancer: the next frontier

Although significant advances have been made in the diagnosis and treatment of breast cancer (BC) in recent years, BC remains the most common cancer in women and one of the main causes of death among women worldwide. Currently, more than half of BC patients have no known risk factors, emphasizing the significance of identifying more tumor-related factors. Therefore, we urgently need to find new therapeutic strategies to improve prognosis. Increasing evidence demonstrates that the microbiota is present in a wider range of cancers beyond colorectal cancer. BC and breast tissues also have different types of microbiotas that play a key role in carcinogenesis and in modulating the efficacy of anticancer treatment, for instance, chemotherapy, radiotherapy, and immunotherapy. In recent years, studies have confirmed that the microbiota can be an important factor directly and/or indirectly affecting the occurrence, metastasis and treatment of BC by regulating different biological processes, such as estrogen metabolism, DNA damage, and bacterial metabolite production. Here, we review the different microbiota-focused studies associated with BC and explore the mechanisms of action of the microbiota in BC initiation and metastasis and its application in various therapeutic strategies. We found that the microbiota has vital clinical value in the diagnosis and treatment of BC and could be used as a biomarker for prognosis prediction. Therefore, modulation of the gut microbiota and its metabolites might be a potential target for prevention or therapy in BC.

16S full-length gene sequencing analysis of intestinal flora in breast cancer patients in Hainan Province

Breast cancer has become the number one cancer in the world, and intestinal flora may be closely linked to it. Geographic location also has an important impact on human intestinal flora. We conducted the first study on the intestinal flora of breast cancer patients and non-breast cancer patients in a tropical region - Hainan Province in China. At the same time, Pacbio platform based on third-generation sequencing was used for the first time to conduct 16S full-length sequencing of fecal microorganism DNA. We completed the species diversity analysis and differential species analysis of the intestinal flora between the two groups, inferred their functional genetic composition and performed functional difference analysis. There were statistically significant differences in alpha diversity between the two groups in Hainan Province. By species composition difference analysis, at the phylum level, Bacteroidales (P = 0.006) and Firmicutes (P = 0.002) was differed between the two groups, and at the genus level, 17 breast cancer-related differential species such as Bacteroides were screened. According to the five grouping methods including ER level, PR level, HER2 status, Ki67 index and histological grade of breast cancer patients, 4, 1, 9, 6, 5 differential microbiota were screened out respectively, which were in total 25 (P < 0.05 for all subgroups) . The functional prediction and difference analysis revealed two functional metabolisms with significant differences between the two groups of microbes (P < 0.05). These results suggest that breast cancer is associated with changes in the composition and function of intestinal flora. These microflora and functional differences may become biomarkers or new targets for diagnosis and treatment of breast cancer.

Comparison of the Fecal Bacteriome of HIV-Positive and HIV-Negative Older Adults

HIV infection is considered a scenario of accelerated aging. Previous studies have suggested a link between aging, frailty, and gut dysbiosis, but there is a knowledge gap regarding the HIV population. Our objective was to compare the fecal bacteriome of older people with HIV (PWH) and non-HIV controls, and to assess potential links between gut dysbiosis and frailty. A total of 36 fecal samples (24 from PWH and 12 from non-HIV controls) were submitted to a metataxonomic analysis targeting the V3-V4 hypervariable region of the 16S rRNA gene. High-quality reads were assembled and classified into operational taxonomic units. Alpha diversity, assessed using the Shannon index, was higher in the control group than in the HIV group (p < 0.05). The relative abundance of the genus Blautia was higher in the HIV group (p < 0.001). The presence of Blautia was also higher in PWH with depression (p = 0.004), whereas the opposite was observed for the genus Bifidobacterium (p = 0.004). Our study shows shifts in the composition of the PWH bacteriome when compared to that of healthy controls. To our knowledge, this is the first study suggesting a potential link between depression and gut dysbiosis in the HIV population.

Elucidating the roles of the mammary and gut microbiomes in breast cancer development

The mammary microbiome is a newly characterized bacterial niche that might offer biological insight into the development of breast cancer. Together with in-depth analysis of the gut microbiome in breast cancer, current evidence using next-generation sequencing and metabolic profiling suggests compositional and functional shifts in microbial consortia are associated with breast cancer. In this review, we discuss the fundamental studies that have progressed this important area of research, focusing on the roles of both the mammary tissue microbiome and the gut microbiome. From the literature, we identified the following major conclusions, (I) There are unique breast and gut microbial signatures (both compositional and functional) that are associated with breast cancer, (II) breast and gut microbiome compositional and breast functional dysbiosis represent potential early events of breast tumor development, (III) specific breast and gut microbes confer host immune responses that can combat breast tumor development and progression, and (IV) chemotherapies alter the microbiome and thus maintenance of a eubiotic microbiome may be key in breast cancer treatment. As the field expectantly advances, it is necessary for the role of the microbiome to continue to be elucidated using multi-omic approaches and translational animal models in order to improve predictive, preventive, and therapeutic strategies for breast cancer.

Identification of Bacterial Metabolites Modulating Breast Cancer Cell Proliferation and Epithelial-Mesenchymal Transition

Breast cancer patients are characterized by the oncobiotic transformation of multiple microbiome communities, including the gut microbiome. Oncobiotic transformation of the gut microbiome impairs the production of antineoplastic bacterial metabolites. The goal of this study was to identify bacterial metabolites with antineoplastic properties. We constructed a 30-member bacterial metabolite library and screened the library compounds for effects on cell proliferation and epithelial-mesenchymal transition. The metabolites were applied to 4T1 murine breast cancer cells in concentrations corresponding to the reference serum concentrations. However, yric acid, glycolic acid, d-mannitol, 2,3-butanediol, and trans-ferulic acid exerted cytostatic effects, and 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, and vanillic acid exerted hyperproliferative effects. Furthermore, 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, 2,3-butanediol, and hydrocinnamic acid inhibited epithelial-to-mesenchymal (EMT) transition. We identified redox sets among the metabolites (d-mannitol-d-mannose, 1-butanol-butyric acid, ethylene glycol-glycolic acid-oxalic acid), wherein only one partner within the set (d-mannitol, butyric acid, glycolic acid) possessed bioactivity in our system, suggesting that changes to the local redox potential may affect the bacterial secretome. Of the nine bioactive metabolites, 2,3-butanediol was the only compound with both cytostatic and anti-EMT properties.

Gender Influences Gut Microbiota among Patients with Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disease that affects approximately 11% of the general population. The gut microbiota, among other known factors, plays a substantial role in its pathogenesis. The study aimed to characterize the gut microbiota differences between patients with IBS and unaffected individuals, taking into account the gender aspect of the patients and the types of IBS determined on the basis of the Rome IV Criteria, the IBS-C, IBS-D, IBS-M, and IBS-U. In total, 121 patients with IBS and 70 unaffected individuals participated in the study; the derived stool samples were subjected to 16S rRNA amplicon sequencing. The gut microbiota of patients with IBS was found to be more diverse in comparison to unaffected individuals, and the differences were observed primarily among Clostridiales, Mogibacteriaceae, Synergistaceae, Coriobacteriaceae, Blautia spp., and Shuttleworthia spp., depending on the study subgroup and patient gender. There was higher differentiation of females' gut microbiota compared to males, regardless of the disease status. No correlation between the composition of the gut microbiota and the type of IBS was found. Patients with IBS were characterized by more diverse gut microbiota compared to unaffected individuals. The gender criterion should be considered in the characterization of the gut microbiota. The type of IBS did not determine the identified differences in gut microbiota.

Human gut, breast, and oral microbiome in breast cancer: A systematic review and meta-analysis

Introduction

Dysbiosis characterises breast cancer through direct or indirect interference in a variety of biological pathways; therefore, specific microbial patterns and diversity may be a biomarker for the diagnosis and prognosis of breast cancer. However, there is still much to determine about the complex interplay of the gut microbiome and breast cancer.

Objective

This study aims to evaluate microbial alteration in breast cancer patients compared with control subjects, to explore intestine microbial modification from a range of different breast cancer treatments, and to identify the impact of microbiome patterns on the same treatment-receiving breast cancer patients.

Methods

A literature search was conducted using electronic databases such as PubMed, Embase, and the CENTRAL databases up to April 2021. The search was limited to adult women with breast cancer and the English language. The results were synthesised qualitatively and quantitatively using random-effects meta-analysis.

Results

A total of 33 articles from 32 studies were included in the review, representing 19 case-control, eight cohorts, and five nonrandomised intervention researches. The gut and breast bacterial species were elevated in the cases of breast tumours, a significant increase in Methylobacterium radiotolerans (p = 0.015), in compared with healthy breast tissue. Meta-analysis of different α-diversity indexes such as Shannon index (p = 0.0005), observed species (p = 0.006), and faint’s phylogenetic diversity (p &lt; 0.00001) revealed the low intestinal microbial diversity in patients with breast cancer. The microbiota abundance pattern was identified in different sample types, detection methods, menopausal status, nationality, obesity, sleep quality, and several interventions using qualitative analysis.

Conclusions

This systematic review elucidates the complex network of the microbiome, breast cancer, and therapeutic options, with the objective of providing a link for stronger research studies and towards personalised medicine to improve their quality of life.

Impact of microbiota on breast cancer hormone therapy

Recent observations indicate that the pathogenesis and prognosis of hormone-receptor breast cancer is not only dictated by the properties of the malignant cells but also by immune and microbial parameters. Thus, the immunosurveillance system retards the development of hormone-positive breast cancer and contributes to the therapeutic efficacy of estrogen receptor antagonists and aromatase inhibitors. Moreover, the anticancer immune response is profoundly modulated by the local and intestinal microbiota, which influences cancer cell-intrinsic signaling pathways, affects the composition and function of the immune infiltrate present in the tumor microenvironment and modulates the metabolism of estrogens. Indeed, specific bacteria in the gut produce enzymes that affect the enterohepatic cycle of estrogen metabolites, convert estrogens into androgens or generate estrogen-like molecules. The knowledge of these circuitries is in its infancy, calling for further in-depth analyses.

Profiling Blautia at high taxonomic resolution reveals correlations with cognitive dysfunction in Chinese children with Down syndrome

Introduction

Down syndrome (DS), the presence of a supernumerary chromosome 21, is associated with cognitive dysfunction caused by early neurodegenerative processes. Alterations in the gut microbiota were observed in Chinese children with DS, and the genus Blautia was associated with cognitive function in these children. Therefore, it is crucial to understand the detailed composition of this group at the species level and to explore the effect of specific species on cognitive function.

Methods

In this study, Blautia-specific amplicon sequencing was conducted to identify the specific Blautia species in 15 children with DS and 15 matched healthy children.

Results

The taxonomic analyses suggested that the Blautia taxa were clustered by disease status. The diversity of Blautia at the species level differed between DS patients and healthy controls, with the abundances of Blautia massiliensis and Blautia argi decreasing in DS children, while Blautia faecis was increased. Acetic acid, one of the metabolites of Blautia, was significantly reduced in the DS group. Of particular interest, Kyoto Encyclopaedia of Genes and Genomes analysis revealed decreased modules related to starch and sucrose metabolism and glycolysis. In addition, B. argi was positively related to DS cognitive scores, and B. faecis was negatively related to cognitive function, implying its role on the DS cognitive impairments.

Discussion

Our study has important implications for understanding the important effects of specific species of Blautia on cognitive function and thus possibly provides a new strategy for future studies of cognitive improvement in individuals with DS.

Breast Cancer Survivors and Healthy Women: Could Gut Microbiota Make a Difference?-"BiotaCancerSurvivors": A Case-Control Study

In this first analysis, samples from 23 BC survivors (group 1) and 291 healthy female controls (group 2) were characterised through the V3 and V4 regions that encode the "16S rRNA" gene of each bacteria. The samples were sequenced by next-generation sequencing (NGS), and the taxonomy was identified by resorting to Kraken2 and improved with Bracken, using a curated database called 'GutHealth_DB'. The α and β-diversity analyses were used to determine the richness and evenness of the gut microbiota. A non-parametric Mann-Whitney U test was applied to assess differential abundance between both groups. The Firmicutes/Bacteroidetes (F/B) ratio was calculated using a Kruskal-Wallis chi-squared test. The α-diversity was significantly higher in group 1 (p = 0.28 × 10^-12 for the Chao index and p = 1.64 × 10^-12 for the ACE index). The Shannon index, a marker of richness and evenness, was not statistically different between the two groups (p = 0.72). The microbiota composition was different between the two groups: a null hypothesis was rejected for PERMANOVA (p = 9.99 × 10^-5) and Anosim (p = 0.04) and was not rejected for β-dispersion (p = 0.158), using Unifrac weighted distance. The relative abundance of 14 phyla, 29 classes, 25 orders, 64 families, 116 genera, and 74 species differed significantly between both groups. The F/B ratio was significantly lower in group 1 than in group 2, p < 0.001. Our study allowed us to observe significant taxonomic disparities in the two groups by testing the differences between BC survivors and healthy controls. Additional studies are needed to clarify the involved mechanisms and explore the relationship between microbiota and BC survivorship.

Breast cancer patients from the Midwest region of the United States have reduced levels of short-chain fatty acid-producing gut bacteria

As geographical location can impact the gut microbiome, it is important to study region-specific microbiome signatures of various diseases. Therefore, we profiled the gut microbiome of breast cancer (BC) patients of the Midwestern region of the United States. The bacterial component of the gut microbiome was profiled utilizing 16S ribosomal RNA sequencing. Additionally, a gene pathway analysis was performed to assess the functional capabilities of the bacterial microbiome. Alpha diversity was not significantly different between BC and healthy controls (HC), however beta diversity revealed distinct clustering between the two groups at the species and genera level. Wilcoxon Rank Sum test revealed modulation of several gut bacteria in BC specifically reduced abundance of those linked with beneficial effects such as Faecalibacterium prausnitzii. Machine learning analysis confirmed the significance of several of the modulated bacteria found by the univariate analysis. The functional analysis showed a decreased abundance of SCFA (propionate) production in BC compared to HC. In conclusion, we observed gut dysbiosis in BC with the depletion of SCFA-producing gut bacteria suggesting their role in the pathobiology of breast cancer. Mechanistic understanding of gut bacterial dysbiosis in breast cancer could lead to refined prevention and treatment.

Gut Microbiota and Breast Cancer: The Dual Role of Microbes

Breast cancer is the most frequently diagnosed cancer and also one of the leading causes of mortality among women. The genetic and environmental factors known to date do not fully explain the risk of developing this disease. In recent years, numerous studies have highlighted the dual role of the gut microbiota in the preservation of host health and in the development of different pathologies, cancer among them. Our gut microbiota is capable of producing metabolites that protect host homeostasis but can also produce molecules with deleterious effects, which, in turn, may trigger inflammation and carcinogenesis, and even affect immunotherapy. The purpose of this review is to describe the mechanisms by which the gut microbiota may cause cancer in general, and breast cancer in particular, and to compile clinical trials that address alterations or changes in the microbiota of women with breast cancer.

The gut microbiota in breast cancer development and treatment: The good, the bad, and the useful!

Regardless of the global progress in early diagnosis and novel therapeutic regimens, breast carcinoma poses a devastating threat, and the advances are somewhat marred by high mortality rates. Breast cancer risk prediction models based on the known risk factors are extremely useful, but a large number of breast cancers develop in women with no/low known risk. The gut microbiome exerts a profound impact on the host health and physiology and has emerged as a pivotal frontier in breast cancer pathogenesis. Progress in metagenomic analysis has enabled the identification of specific changes in the host microbial signature. In this review, we discuss the microbial and metabolomic changes associated with breast cancer initiation and metastatic progression. We summarize the bidirectional impact of various breast cancer-related therapies on gut microbiota and vice-versa. Finally, we discuss the strategies to modulate the gut microbiota toward a more favorable state that confers anticancer effects.

Lacticaseibacillus rhamnosus Probio-M9-Driven Mouse Mammary Tumor-Inhibitory Effect Is Accompanied by Modulation of Host Gut Microbiota, Immunity, and Serum Metabolome

Gut microbiome may influence tumor growth and cancer treatment efficacy, so it is a potential target for tumor prevention/treatment. This pilot study investigated the preventive and therapeutic effects of a probiotic strain, Lacticaseibacillus rhamnosus Probio-M9 (Probio-M9), against murine mammary cancer. Thirty-six female mice were randomly divided into three groups (n = 12 per group): control (without tumor transplantation), model (tumor transplantation; no probiotic administration), and probiotic (30-day oral gavage of probiotic, started seven days before tumor transplantation). Changes in tumor size were recorded, and blood, tumor tissue, and stool samples were collected at the end of the trial for analyses. Comparing with the model group, the probiotic group had a significantly smaller tumor volume (p < 0.05), a higher fecal microbiota Shannon diversity index, with significant modifications in the gut microbiota structure (p < 0.05), characterized by more Alistipes sp._2, Porphyromonadaceae bacterium_7, and Bacteroidales bacterium 55_9 (p < 0.05). Additionally, Probio-M9 administration elevated the serum IFN-γ, IL-9, IL-13, and IL-27 levels and several metabolites (e.g., pyridoxal, nicotinic acid, 3-hydroxybutyric acid, glutamine; p < 0.05), while reducing IL-5 (p < 0.05). These changes might be associated with the protective effect of Probio-M9 against mammary tumor growth. Thus, probiotic administration could harness host gut microbiome in anti-cancer responses.

Effect of Chemotherapy on the Gut Microbiome of Breast Cancer Patients During the First Year of Treatment

INTRODUCTION

There is accumulating information of the effects of chemotherapy and weight changes on the gut microbiome of breast cancer patients.

METHODS

In this 1-year follow-up study, we investigated gut microbiome of 33 breast cancer patients who donated fecal samples at baseline and after completion of treatment. We compared alpha diversity and mean taxa abundance at baseline and absolute taxa abundance changes (final-baseline) by treatment (16 neoadjuvant [neoADJ], 13 adjuvant [ADJ], 4 no chemotherapy [noC]) and specific chemotherapy agent using Wilcoxon rank sum and negative binomial mixed model (NBMM) analysis.

RESULTS

All four gut alpha diversity measures changed in association with chemotherapy treatment; they increased in the neoADJ (+16.4% OTU p = 0.03; +51.6% Chao1 p = 0.03; +7.0% Shannon index p = 0.02; +11.0% PD whole tree p = 0.09) but not in the ADJ and noC group (ADJ+noC). The difference in Chao1 index change between groups was statistically significant (pneoADJ vs. ADJ+noC=0.04). Wilcoxon p values of 0.03-0.003 were observed for five taxa. In NBMM analysis, changes in taxa abundance differed (Bonferroni-adjusted p ≤ 0.0007) for two Bacteroidetes taxa (g_Alistipes, f_S24-7) and two Firmicutes taxa (g_Catenibacterium, g_Eubacterium). NBMM analysis results remained unchanged with adjustment for weight changes. Alpha diversity changes were also found by receipt of chemotherapy agents. Consistent increases in alpha diversity were observed among those treated with TCHP (OTU p = 0.009; Chao1 p = 0.02; Shannon p = 0.02; PD whole tree p = 0.05) but not AC, Taxol or Herceptin. Those treated with TCHP or Herceptin showed increases in Verrucomicrobia (g_Akkermansia) but decreases of Bacteroidetes(g_Alistipes); the differences in changes in taxa abundance were statistically significant.

CONCLUSION

Results from this pilot longitudinal study support an effect of chemotherapy, particularly neoADJ on the gut microbiome of breast cancer patients even after adjustment for weight changes. Further investigations are needed to confirm these findings in larger studies and with longer follow-up and to assess the impact of these microbiome changes on patient outcome.

Impact of intestinal dysbiosis on breast cancer metastasis and progression

Breast cancer has a high mortality rate among malignant tumors, with metastases identified as the main cause of the high mortality. Dysbiosis of the gut microbiota has become a key factor in the development, treatment, and prognosis of breast cancer. The many microorganisms that make up the gut flora have a symbiotic relationship with their host and, through the regulation of host immune responses and metabolic pathways, are involved in important physiologic activities in the human body, posing a significant risk to health. In this review, we build on the interactions between breast tissue (including tumor tissue, tissue adjacent to the tumor, and samples from healthy women) and the microbiota, then explore factors associated with metastatic breast cancer and dysbiosis of the gut flora from multiple perspectives, including enterotoxigenic Bacteroides fragilis, antibiotic use, changes in gut microbial metabolites, changes in the balance of the probiotic environment and diet. These factors highlight the existence of a complex relationship between host-breast cancer progression-gut flora. Suggesting that gut flora dysbiosis may be a host-intrinsic factor affecting breast cancer metastasis and progression not only informs our understanding of the role of microbiota dysbiosis in breast cancer development and metastasis, but also the importance of balancing gut flora dysbiosis and clinical practice.

Microbial dysbiosis and epigenetics modulation in cancer development - A chemopreventive approach

An overwhelming number of research articles have reported a strong relationship of the microbiome with cancer. Microbes have been observed more commonly in the body fluids like urine, stool, mucus of people with cancer compared to the healthy controls. The microbiota is responsible for both progression and suppression activities of various diseases. Thus, to maintain healthy human physiology, host and microbiota relationship should be in a balanced state. Any disturbance in this equilibrium, referred as microbiome dysbiosis becomes a prime cause for the human body to become more prone to immunodeficiency and cancer. It is well established that some of these microbes are the causative agents, whereas others may encourage the formation of tumours, but very little is known about how these microbial communications causing change at gene and epigenome level and trigger as well as encourage the tumour growth. Various studies have reported that microbes in the gut influence DNA methylation, DNA repair and DNA damage. The genes and pathways that are altered by gut microbes are also associated with cancer advancement, predominantly those implicated in cell growth and cell signalling pathways. This study exhaustively reviews the current research advancements in understanding of dysbiosis linked with colon, lung, ovarian, breast cancers and insights into the potential molecular targets of the microbiome promoting carcinogenesis, the epigenetic alterations of various potential targets by altered microbiota, as well as the role of various chemopreventive agents for timely prevention and customized treatment against various types of cancers.

Hedgehog blockade remodels the gut microbiota and the intestinal effector CD8+ T cells in a mouse model of mammary carcinoma

Given the gut microbiome's rise as a potential frontier in cancer pathogenesis and therapy, leveraging microbial analyses in the study of breast tumor progression and treatment could unveil novel interactions between commensal bacteria and disease outcomes. In breast cancer, the Hedgehog (Hh) signaling pathway is a potential target for treatment due to its aberrant activation leading to poorer prognoses and drug resistance. There are limited studies that have investigated the influences of orally administered cancer therapeutics, such as Vismodegib (a pharmacological, clinically used Hh inhibitor) on the gut microbiota. Using a 4T1 mammary carcinoma mouse model and 16 S rRNA sequencing, we longitudinally mapped alterations in immunomodulating gut microbes during mammary tumor development. Next, we identified changes in the abundance of commensal microbiota in response to Vismodegib treatment of 4T1 mammary tumor-bearing mice. In addition to remodeling gut microbiota, Vismodegib treatment elicited an increase in proliferative CD8⁺ T cells in the colonic immune network, without any remarkable gastrointestinal-associated side effects. To our knowledge, this is the first study to assess longitudinal changes in the gut microbiome during mammary tumor development and progression. Our study also pioneers an investigation of the dynamic effects of an orally delivered Hh inhibitor on the gut microbiome and the gut-associated immune-regulatory adaptive effector CD8⁺ T cells. These findings inform future comprehensive studies on the consortium of altered microbes that can impact potential systemic immunomodulatory roles of Vismodegib.

Dysbiosis of Ocular Surface Microbiota in Patients With Refractive Allergic Conjunctival Diseases

PURPOSE

We investigated ocular surface microbiota dysbiosis in patients with refractory allergic conjunctival diseases (ACDs; stratified into mild and severe groups) treated with topical tacrolimus.

METHODS

Patients (n = 21) with refractory ACDs (including vernal and atopic keratoconjunctivitis) actively treated with topical tacrolimus and 6 healthy controls were evaluated. Based on clinical scores and expression of specific cytokines on the ocular surface, patients with ACDs were divided into mild and severe groups using cluster analysis. The microbial composition of tear specimens collected from patients with mild and severe ACD and control subjects using the Schirmer test paper was determined through next-generation 16S rRNA sequencing analysis.

RESULTS

Compared with healthy controls, patients with ACDs exhibited significantly decreased ocular surface microbiota α-diversity. Ocular surface microbiota mainly comprised members of the phyla Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria in all groups. The relative abundance of ocular surface microbiota in patients with ACDs was increased for phylum Firmicutes and decreased for phylum Proteobacteria (compared with control subjects). The genera Blautia (vs. mild ACD group) and Morganella (vs. control group) exhibited significantly increased abundance only in the severe ACD group.

CONCLUSIONS

The ocular surface microbiota in patients with severe ACD exhibited decreased diversity and exacerbation of dysbiosis compared with that in patients with mild ACD and control subjects. Patients with mild refractory ACD also exhibited decreased diversity of these microbiota. These alterations in microbiota indicated a change in the ocular surface of patients with refractory ACD (be it because of disease pathogenesis or topical immunomodulatory treatment).

Modulating Microbiota as a New Strategy for Breast Cancer Prevention and Treatment

Breast cancer (BC) is the most common cancer in women in the United States. There has been an increasing incidence and decreasing mortality rate of BC cases over the past several decades. Many risk factors are associated with BC, such as diet, aging, personal and family history, obesity, and some environmental factors. Recent studies have shown that healthy individuals and BC patients have different microbiota composition, indicating that microbiome is a new risk factor for BC. Gut and breast microbiota alterations are associated with BC prognosis. This review will evaluate altered microbiota populations in gut, breast tissue, and milk of BC patients, as well as mechanisms of interactions between microbiota modulation and BC. Probiotics and prebiotics are commercially available dietary supplements to alleviate side-effects of cancer therapies. They also shape the population of human gut microbiome. This review evaluates novel means of modulating microbiota by nutritional treatment with probiotics and prebiotics as emerging and promising strategies for prevention and treatment of BC. The mechanistic role of probiotic and prebiotics partially depend on alterations in estrogen metabolism, systematic immune regulation, and epigenetics regulation.

Gut microbiota: Role and Association with Tumorigenesis in Different Malignancies

The microbiota has been associated with different cancer and may vary from patient to patient. A specific microbial strain can alter the progression of cancer and therapeutic outcome in response to anti-cancer therapy. The variations in microbiota contributed due to the individual microbiome of the microorganism are responsible for diverse clinical outcomes. The expansion of microbiota subpopulation during dysbiosis can lead to toxin production, inducing inflammation and cancer. The microbiota can be a dual-edged sword because it can be tumor-suppressive or oncogenic in the case of the gut. The transition of cancer cells from early to late-stage also impacts the composition of the microbiota, and this alteration could change the behavior of cancer. Multi-omics platforms derived data from an individual's multi-dimensional data (DNA, mRNA, microRNA, protein, metabolite, microbiota, and microbiome), i.e., individualome, to exploit it for personalized tailored treatment for different cancers in a precise manner. A number of studies suggest the importance of microbiota and its add-in suitability to existing treatment options for different malignancies. Furthermore, in vitro, and in vivo studies and cancer clinical trials suggest that probiotics have driven modulation of gut microbiota and other sites discourage the aggressive behavior and progression of different cancers.

Dynamics of gut microbiota during pregnancy in women with TPOAb-positive subclinical hypothyroidism: a prospective cohort study

Background

Anti-thyroid peroxidase antibody (TPOAb) positivity can contribute to inhibit thyroxine synthesis. Gut microbiota can interact with metabolic or immune diseases. However, dynamics of gut microbiota from the second (T2) to the third trimester (T3) in women with TPOAb-positive/negative subclinical hypothyroidism (TPOAb⁺/TPOAb⁻ SCH) have not been reported. Therefore, we aimed to evaluate whether gut microbiota can be potential therapeutic targets for managing TPOAb⁺ SCH.

Methods

In this single-center prospective cohort study, we observed gut microbiota dynamics by sequencing 16S rRNA from fecal samples collected in T2 (20–23^+ 6 weeks) and T3 (28–33^+ 6 weeks). TPOAb⁺/TPOAb⁻ SCH were stratified depending on whether or not they used levothyroxine (LT₄) during the pregnancy (LT₄⁺/LT₄⁻). Microbiome bioinformatics analyses were performed using QIIME2. The linear discriminant analysis effect size (LEfSe) was used for the quantitative analysis of biomarkers. Functional profiling was performed with PICRUSt2.

Results

Distinct gut microbiota dynamics from T2 to T3 were noted in the TPOAb⁻ (n = 68) and TPOAb⁺ (n = 64) SCH groups. The TPOAb⁺ LT₄⁻ group was characterized by enriched bacterial amplicon sequence variants (ASVs) of Prevotella in T2 and Bacteria, Lachnospirales, Lachnospiraceae, Blautia, and Agathobacter in T3 and by depleted ASVs of Gammaproteobacteria, Enterobacterales, and Enterobacteriaceae in T2 and Actinobacteriota, Coriobacteriia, Actinobacteria, Coriobacteriales, Bifidobacteriales, Bifidobacteriaceae, Bifidobacterium, Dorea formicigenerans, and Bifidobacterium longum in T3. The TPOAb⁺ LT₄⁺ group was characterized by enriched bacterial ASVs of Blautia, Streptococcus salivarius, and Bifidobacterium longum in T3 and by depleted ASVs of Bacteroidota, Bacteroidia, Bacteroidales, and Prevotella in T2 and Agathobacter in T3. Moreover, we identified 53 kinds of metabolic functions that were mainly involved in sugar, lipid, and amino acid metabolism.

Conclusions

Our results indicated that low dynamics of gut microbiota composition and high dynamics of its metabolic function from T2 to T3 were associated with TPOAb⁺ SCH. We concluded that gut microbiota could be new targets for treatment of TPOAb⁺ SCH during pregnancy.

Trial registration

This study was retrospectively registered at the Chinese Clinical Trial Registry (registration number ChiCTR2100047175) on June 10, 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04923-5.

Targeting gut microbiota to alleviate neuroinflammation in Alzheimer's disease

The gut microbiota came into focus within the last years regarding being associated with or even underlying neuropsychiatric diseases. The existence of the gut-brain-axis makes it highly plausible that bacterial metabolites or toxins that escape the intestinal environment or approach the vagal connections towards the brain, exert devastating effects on the central nervous system. In Alzheimer's disease (AD), growing evidence for dysbiotic changes in the gut microbiota is obtained, even though the question for cause or consequence remains open. Nevertheless, using modulation of microbiota to address inflammatory processes seems an attractive therapeutic approach as certain microbial products such as short chain fatty acids have been proven to exert beneficial cognitive effects. In this review, we summarize, contemporary knowledge on neuroinflammation and inflammatory processes within the brain and even more detailed in the gut in AD, try to conclude whom to target regarding human microbial commensals and report on current interventional trials.

Body Microbiota and Its Relationship With Benign and Malignant Breast Tumors: A Systematic Review

Breast cancer is the most frequent type of cancer as well as one of the main causes of cancer-related mortality in women. Human microbial dysbiosis, which has been related to a range of malignancies, is one of the variables that may impact the chance of developing breast disorders. In this review, we aimed to investigate the relationship between breast cancer and benign breast tumors with dysbiosis of the microbiome at different body sites. We performed a systematic review of MEDLINE, Scopus, Ovid, and Cochrane Library to identify original articles published until July 2020 that reported studies of breast disease and microbiota. Twenty-four original articles were included in the study, which looked at the features and changes in breast, gut, urine, lymph node, and sputum microbial diversity in patients with benign and malignant breast tumors. In breast cancer, the breast tissue microbiome demonstrated changes in terms of bacterial load and diversity; in benign breast tumors, the microbiome was more similar to a malignant tumor than to normal breast tissue. Triple-negative (TNBC) and triple-positive (TPBC) types of breast cancer have a distinct microbial pattern. Moreover, in breast cancer, gut microbiota displayed changes in the compositional abundance of some bacterial families and microbial metabolites synthesis. Our review concludes that breast carcinogenesis seems to be associated with microbial dysbiosis. This information can be further explored in larger-scale studies to guide new prophylactic, diagnostic, and therapeutic measures for breast cancer.

Variations in the Gut Microbiota in Breast Cancer Occurrence and Bone Metastasis

Breast cancer is the most common cancer in women and the second most common cancer overall. Although advancements in the early diagnosis and therapy of breast cancer have occurred in recent years, the prognosis of breast cancer bone metastasis remains poor and this type of cancer is rarely cured. The gut microbiota is indispensable for internal homeostasis and regulates various biological processes. Understanding the gut microbiota profiles in normal controls (NCs), breast cancer patients with no metastasis (BNs), and breast cancer patients with bone metastasis (BMs) may shed light on the development of diagnostic and therapeutic targets for breast cancer and bone metastasis. We comprehensively analyzed the gut microbiota from NCs, BNs, and BMs and found that the community diversity decreased in the order of NCs, BNs, and BMs. Streptococcus, Campylobacter and Moraxellaceae showed higher abundances in BNs and BMs than in NCs. The lack of Megamonas and Akkermansia in the BM compared with those in the NC and BN groups was considered related to bone metastasis. Additionally, based on the distinct gut microbiota profiles, we predicted that lipid transportation and metabolism, as well as folate biosynthesis, participate in breast cancer occurrence and that steroid hormone biosynthesis influences bone metastasis. Our study demonstrated that variations in gut microbiota are associated with breast cancer occurrence and bone metastasis, providing attractive targets to develop therapeutic and diagnostic methods.

New Developments and Opportunities of Microbiota in Treating Breast Cancers

Despite the prevalence of breast cancer (BC), over half of BC cases are unrelated to known risk factors, which highlights the importance of uncovering more cancer-related factors. Currently, the microbiota has been proven to be a potent modulator of the tumor environment in BC, which regulates the immune balance in tumor-related networks. Through a large amount of data accumulation, the microbiota has shown many possibilities to reveal more insights into the development or control of BC. To expand the potential benefits of patients with BC, this study discusses the distribution profile and the effect mechanism of BC-related microbiota on tumors and further discusses its impact on different tumor therapies. Finally, we summarize the possibility of targeting microbiological therapies to improve BC treatment or in combination with other therapies.

Identification of tissue-specific microbial profile of esophageal squamous cell carcinoma by full-length 16S rDNA sequencing

It was previously believed that the microbial community in the esophagus was relatively stable, but it has been reported that different esophageal diseases have different microbial community characteristics. In this study, we recruited patients with esophageal squamous cell carcinoma (ESCC) and collected 51 pairs of tumor and adjacent non-tumor tissues for full-length 16S rDNAsequencing and qPCR to compare the differences in microbial community structure. The results of sequencing in 19 pairs of tissues showed that Proteobacteria, Firmicutes, Bacteroidetes, Deinococcus-Thermus, and Actinobacteria were the main bacteria in tumor and adjacent non-tumor tissues. At the genus level, the bacteria with the highest relative proportion in tumor and adjacent non-tumor tissues were Streptococcus and Labrys, respectively. At the same time, it was observed that the complexity of microbial interactions in tumor tissues was weaker than that of adjacent non-tumor tissues. The results also found that the relative abundance of 24 taxa was statistically different between tumor and adjacent non-tumor tissues. The findings of qPCR in 32 pairs of tissues further evidence that the relative proportions of Blautia, Treponema, Lactobacillus murinus, Peptoanaerobacter stomatis, and Fusobacteria periodonticum were statistically different in tumor and adjacent non-tumor tissues. The findings of PIRCUSt2 indicated the lipopolysaccharide biosynthesis and biotin metabolism in the microbiome of cancer tissues are more significant. This study supplements the existing information on the structure, function, and interaction of microorganisms in the esophagus in situ and provides a direction for the further exploration of the relationship between esophageal in situ microorganisms and esophageal squamous cell carcinoma. KEY POINTS: • The structure of the microbial community in esophageal cancer tissue and adjacent non-tumor tissues at the phylum level is similar • Streptococcus and Labrys are the most important bacteria in esophageal tumor tissues and adjacent non-tumor tissues, respectively • Microbial interactions in tumor tissues are stronger than in adjacent non-tumor tissues.