Probiotic bacteria in cancer patients undergoing chemotherapy and radiation therapy

Growth Suppression of Oral Squamous Cell Carcinoma Cells by Lactobacillus Acidophilus

OBJECTIVES

Oral squamous cell carcinoma (OSCC) is a highly aggressive form of oral cancer. Probiotic lactobacilli have demonstrated anticancer effects, whilst their interaction with Streptococcus mutans in this context remains unexplored. The objective of this study was to investigate the antiproliferative effect of Lactobacillus acidophilus on OSCC and to understand the effect of S mutans on OSCCs and whether it affects the antiproliferative potential of L acidophilus when co-exposed to OSCC.

METHODS

The human head and neck squamous cell carcinoma cells of the oral cavity (HNO97 cell line) were exposed to cultures of L acidophilus and S mutans separately and in combination. Further, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to assess the viability of HNO97 cells. Bacterial adhesion to HNO97 cells was examined by confocal microscopy and apoptosis by Nexin staining. To understand the underlying mechanism of apoptosis, expression of the tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) gene and protein were determined by real-time polymerase chain reaction and quantitative enzyme-linked immunosorbent assay, respectively.

RESULTS

A significant decrease (53%-56%) in the viability of HNO97 cells on exposure to L acidophilus, S mutans, and the 2 species together demonstrated the antiproliferative activity of L acidophilus and S mutans. Both bacteria showed adhesion to HNO97 cells. The expression of the TRAIL gene increased 5-fold in HNO97 cells on treatment with L acidophilus and S mutans, which further increased to ∼17-fold with both species present. Expression levels of the TRAIL protein were significantly (P < .05) increased in bacteria-treated cell lysates. Further, bacteria-treated HNO97 cells exhibited lower live and intact cell percentages with higher proportions of cells in early and late apoptotic stages.

CONCLUSIONS

L acidophilus exhibits the antiproliferative activity against OSCC cells possibly partially via a TRAIL-induced mechanism of apoptosis, which is not affected by the presence of S mutans. These findings may encourage further investigation into the possible therapeutic application of probiotic L acidophilus in OSCC.

Bacterial supplementation in mitigation of radiation-induced gastrointestinal damage

Pelvic irradiation, a crucial treatment for pelvic malignancies, is associated with the risk of gastrointestinal (GI) damage due to the high proliferation rate of epithelial cells. The radiosensitive gastrointestinal tract acts as a dose-limiting organ. High doses of ionizing radiation can cause inflammation and rupture of mucosal barriers and can also lead to intestinal fibrosis. Intestinal damage can cause acute to chronic complications, reducing patients' quality of life. The gut microbiota plays a vital role in maintaining gut health, and any changes in the gut microbial composition can worsen damage, emphasizing the importance of therapies that target and sustain the gut microbiota during radiotherapy. One potential strategy to prevent radiation-induced GI damage is to use bacterial supplements. Research suggests that probiotic supplementation may alleviate radiation-induced gastrointestinal damage, maintaining intestinal morphology and decreasing epithelial injury in cancer patients. The observed protective effects occur through various mechanisms, including antioxidant activities, modulation of the immune response, and preservation of gut barrier function. To optimize probiotic therapies, it is imperative to elucidate these mechanisms. The efficiency of probiotics as radioprotectors is highly dependent on the time and dose of administration, and their interaction with the host immune system is a key facet of their therapeutic potential. This review explores the potential benefits of bacterial supplementation in mitigating radiation-induced GI damage and the underlying mechanism. This highlights the need for further research to establish standardized protocols and refine probiotic supplementation strategies, underscoring the potential for enhancing therapeutic outcomes in patients undergoing pelvic radiotherapy.

Potential of Synbiotics and Probiotics as Chemopreventive Agent

Cancer remains a global problem, with millions of new cases diagnosed yearly and countless lives lost. The financial burden of cancer therapy, along with worries about the long-term safety of existing medicines, necessitates the investigation of alternative approaches to cancer prevention. Probiotics generate chemopreventive compounds such as bacteriocins, short-chain fatty acids (SCFA), and extracellular polymeric substances (EPS), which have demonstrated the ability to impede cancer cell proliferation, induce apoptosis, and bolster the expression of pro-apoptotic genes. On the other hand, prebiotics, classified as non-digestible food ingredients, promote the proliferation of probiotics within the colon, thereby ensuring sustained functionality of the gut microbiota. Consequently, the synergistic effect of combining prebiotics with probiotics, known as the synbiotic effect, in dietary interventions holds promise for potentially mitigating cancer risk and augmenting preventive measures. The utilization of gut microbiota in cancer treatment has shown promise in alleviating adverse health effects. This review explored the potential and the role of probiotics and synbiotics in enhancing health and contributing to cancer prevention efforts. In this review, the applications of functional probiotics and synbiotics, the mechanisms of action of probiotics in cancer, and the relationship of probiotics with various drugs were discussed, shedding light on the potential of probiotics and synbiotics to alleviate the burdens of cancer treatment.

Role of the Microbiome in the Diagnosis and Management of Gastroesophageal Cancers

PURPOSE

Stomach and esophageal cancers are among the highest mortality from cancers worldwide. Microbiota has an interplaying role within the human gastrointestinal (GI) tract. Dysbiosis occurs when a disruption of the balance between the microbiota and the host happens. With this narrative review, we discuss the main alterations in the microbiome of gastroesophageal cancer, revealing its potential role in the pathogenesis, early detection, and treatment.

RESULTS

Helicobacter pylori plays a major role the development of a cascade of preneoplastic conditions ranging from atrophic gastritis to metaplasia and dysplasia, ultimately culminating in gastric cancer, while other pathogenic agents are Fusobacterium nucleatum, Bacteroides fragilis, Escherichia coli, and Lactobacillus. Campylobacter species (spp.)'s role in the progression of esophageal adenocarcinoma may parallel that of Helicobacter pylori in the context of gastric cancer, with other esophageal carcinogenic agents being Escherichia coli, Bacteroides fragilis, and Fusobacterium nucleatum. Moreover, gut microbiome could significantly alter the outcomes of chemotherapy and immunotherapy. The gut microbiome can be modulated through interventions such as antibiotics, probiotics, or prebiotics intake. Fecal microbiota transplantation has emerged as a therapeutic strategy as well.

CONCLUSIONS

Nowadays, it is widely accepted that changes in the normal gut microbiome causing dysbiosis and immune dysregulation play a role gastroesophageal cancer. Different interventions, including probiotics and prebiotics intake are being developed to improve therapeutic outcomes and mitigate toxicities associated with anticancer treatment. Further studies are required in order to introduce the microbiome among the available tools of precision medicine in the field of anticancer treatment.

It Is All about Probiotics to Control Cervical Cancer

Cervical cancer (CC) is the fourth most common malignancy in female patients. "Human papillomavirus" (HPV) contamination is a leading cause of all forms of cervical cancer, accounting for an expected 570,000 reported incidents in 2018. Two HPV strains (16 and 18) are responsible for 70% of CC and pre-cancerous cervical abnormalities. CC is one of the foremost reasons for the malignancy death rate in India among women ranging from 30 to 69 years of age in India, responsible for 17% of all cancer deaths. Currently approved cervical cancer treatments are associated with adverse reactions that might harm the lives of women affected by this disease. Consequently, probiotics can play a vital role in the treatment of CC. It is reflected from various studies regarding the role of probiotics in the diagnosis, prevention or treatment of cancer. In this review article, we have discussed the rationale of probiotics for treatment of CC, the role of probiotics as effective adjuvants in anti-cancer therapy and the combined effect of the anti-cancer drug along with probiotics to minimize the side effects due to chemotherapy.

Anticancer Potential of Postbiotic Derived from Lactobacillus brevis and Lactobacillus casei: In vitro Analysis of Breast Cancer Cell Line

Breast cancer has emerged as the most widespread and dangerous type of malignancy among women worldwide. Postbiotics have recently emerged as a promising novel adjunct in breast cancer therapy, due to their immunomodulatory effects and the potential to mitigate the adverse effects of conventional treatments. This study aims to investigate the therapeutic effects of postbiotics derived from Lactobacillus brevis (CSF2) and Lactobacillus casei (CFS5), specifically examining their ability to inhibit cell proliferation and induce apoptosis in MCF-7 breast cancer cells. In the current study, the anticancer activity of the cell-free supernatant of L. brevis and L. casei was investigated against MCF-7 cells using MTT assay, flow cytometry, and qRT-PCR technique. Both bacteria showed a high potential for the induction of cell death in MCF-7 cells. However, CFS2 cytotoxicity was significantly higher than CFS5. Flow cytometry results showed significant induction of early apoptosis in cells treated with both CFS2 and CFS5 within 48 h. The induction was notably higher in cells treated with CFS2 compared to CFS5. Overall, CFS2 therapy resulted in a greater increase in BAX and CASP9 gene expression, as well as an elevated BAX/BCL2 ratio within 48 h. These findings indicate that the CFS2 treatment showed a higher level of apoptotic activity than the CFS5 treatment. High biocompatibility was demonstrated following treatment with CFS2 and CFS5. These CFSs may serve as adjunctive medications for suppressing the proliferation of cancer cells. The results of the current study highlight the potential of postbiotics in cancer treatment and suggest that supernatants may serve as effective agents for suppressing cancer cell growth and viability.

Gastric Cancer, Immunotherapy, and Nutrition: The Role of Microbiota

Immune checkpoint inhibitors (ICI) have revolutionized the treatment of gastric cancer (GC), which still represents the third leading cause of cancer-related death in Western countries. However, ICI treatment outcomes vary between individuals and need to be optimized. Recent studies have shown that gut microbiota could represent a key influencer of immunotherapy responses. At the same time, the nutritional status and diet of GC patients are also predictive of immunotherapy treatment response and survival outcomes. The objective of this narrative review is to gather recent findings about the complex relationships between the oral, gastric, and gut bacterial communities, dietary factors/nutritional parameters, and immunotherapy responses. Perigastric/gut microbiota compositions/functions and their metabolites could be predictive of response to immunotherapy in GC patients and even overall survival. At the same time, the strong influence of diet on the composition of the microbiota could have consequences on immunotherapy responses through the impact of muscle mass in GC patients during immunotherapy. Future studies are needed to define more precisely the dietary factors, such as adequate daily intake of prebiotics, that could counteract the dysbiosis of the GC microbiota and the impaired nutritional status, improving the clinical outcomes of GC patients during immunotherapy.

The Hazards of Probiotics on Gut-Derived Pseudomonas aeruginosa Sepsis in Mice Undergoing Chemotherapy

Pseudomonas aeruginosa (P. aeruginosa) is a leading cause of nosocomial infections associated with a high mortality rate and represents a serious threat to human health and the increasing frequency of antimicrobial resistance. Cancer patients are more vulnerable to invasive infection due to ulcerative lesions in mucosal surfaces and immune suppression secondary to chemotherapy. In our in vitro study, we observed that probiotics have the potential to yield beneficial effects on intestinal epithelial cells infected with P. aeruginosa. Additionally, probiotics were found to confer advantageous effects on the innate immunity of mice suffering from Salmonella-induced colitis. As a result, we sought to investigate the impact of probiotics on gut-derived P. aeruginosa sepsis induced by chemotherapy. Following chemotherapy, gut-derived P. aeruginosa sepsis was induced in female C57BL/6 mice aged 6-8 weeks, which were raised under specific-pathogen-free (SPF) conditions in an animal center. Prior to the induction of the sepsis model, the mice were administered 1 × 108 colony-forming units (CFU) of the probiotics, namely Lactobacillus rhamnosus GG (LGG) and Bifidobacterium longum (BL) via oral gavage. We observed that LGG or BL amplified the inflammatory mRNA expression in mice undergoing chemotherapy and suffering from gut-derived P. aeruginosa sepsis. This led to a heightened severity of colitis, as indicated by histological examination. Meanwhile, there was a notable decrease in the expression of antimicrobial peptide mRNA along with reduced levels of zonulin and claudin-2 protein staining within mucosal tissue. These alterations facilitated the translocation of bacteria to the liver, spleen, and bloodstream. To our astonishment, the introduction of probiotics exacerbated gut-derived P. aeruginosa sepsis in mice undergoing chemotherapy. Conclusively, we must be prudent when using probiotics in mice receiving chemotherapy complicated with gut-derived P. aeruginosa sepsis.

Investigating the Influence of Gut Microbiota-related Metabolites in Gastrointestinal Cancer

Gastrointestinal (GI) cancer is a major health concern due to its prevalence, impact on well-being, high mortality rate, economic burden, and potential for prevention and early detection. GI cancer research has made remarkable strides in understanding biology, risk factors, and treatment options. An emerging area of research is the gut microbiome's role in GI cancer development and treatment response. The gut microbiome, vital for digestion, metabolism, and immune function, is increasingly linked to GI cancers. Dysbiosis and alterations in gut microbe composition may contribute to cancer development. Scientists study how specific bacteria or microbial metabolites influence cancer progression and treatment response. Modulating the gut microbiota shows promise in enhancing treatment efficacy and preventing GI cancers. Gut microbiota dysbiosis can impact GI cancer through inflammation, metabolite production, genotoxicity, and immune modulation. Microbes produce metabolites like short-chain fatty acids, bile acids, and secondary metabolites. These affect host cells, influencing processes like cell proliferation, apoptosis, DNA damage, and immune regulation, all implicated in cancer development. This review explores the latest research on gut microbiota metabolites and their molecular mechanisms in GI cancers. The hope is that this attempt will help in conducting other relevant research to unravel the precise mechanism involved, identify microbial signatures associated with GI cancer, and develop targets.

The effects of synbiotics supplementation on reducing chemotherapy-induced side effects in women with breast cancer: a randomized placebo-controlled double-blind clinical trial

BACKGROUND

The prevalence of breast cancer and its mortality rate are increasing rapidly among women worldwide. On other hand, the courses of chemotherapy as the main treatment for these patients are too much exhaustive and annoying. This study was designed to evaluate the use of synbiotics (probiotics + prebiotics) supplementation as a safe and inexpensive adjuvant treatment in reducing common chemotherapy side effects in women with breast cancer.

METHODS

The current study was conducted on 67 women with definitive diagnosis of breast cancer who were hospitalized to receive one-day chemotherapy sessions, and met the inclusion criteria. The patients were randomly allocated to the intervention or control group to receive synbiotics or placebo, respectively. They received oral consumption of synbiotics supplements twice a day for 8 weeks. The primary outcome was the changes in severity or experience of chemotherapy complication, analyzed by intention to treat (ITT). The instruments included 7 validated questionnaires which were used to assess chemotherapy complications in the initiation, 4 weeks and 8 weeks after intervention. Dietary intake was measured by 24-h dietary recall at the beginning, week 4 and week 8. Data were analyzed by SPSS software version 24. P-value < 0.05 was considered as statistically significant.

RESULTS

67 breast cancer patients participated in the study. 8 weeks after intervention and adjusting the confounders, the severity of chemotherapy complications including unnormal defecation (P = 0.005) and fatigue (P < 0/001) decreased significantly in the synbiotics group compared to the placebo group. Furthermore, nausea/vomiting (P = 0.015), and anorexia (P < 0.001) were decreased at the end of the study compared to the first visit, but it was not statistically significant compared to the placebo group.

CONCLUSIONS

Synbiotics supplementation during chemotherapy can potentially reduce the severity of fatigue and abnormal defecation. It can help reduce anorexia and nausea/vomiting.

TRIAL REGISTRATION

This study was registered in the Iranian Registry of Clinical Trials (IRCT) (registered code: IRCT20091114002709N56) (date of registration: 5/5/2021). Direct link to the trial page: https://www.irct.ir/trial/54559 .

The effects of synbiotics supplementation on reducing chemotherapy-induced side effects in women with breast cancer: a randomized placebo-controlled double-blind clinical trial

BACKGROUND

The prevalence of breast cancer and its mortality rate are increasing rapidly among women worldwide. On other hand, the courses of chemotherapy as the main treatment for these patients are too much exhaustive and annoying. This study was designed to evaluate the use of synbiotics (probiotics + prebiotics) supplementation as a safe and inexpensive adjuvant treatment in reducing common chemotherapy side effects in women with breast cancer.

METHODS

The current study was conducted on 67 women with definitive diagnosis of breast cancer who were hospitalized to receive one-day chemotherapy sessions, and met the inclusion criteria. The patients were randomly allocated to the intervention or control group to receive synbiotics or placebo, respectively. They received oral consumption of synbiotics supplements twice a day for 8 weeks. The primary outcome was the changes in severity or experience of chemotherapy complication, analyzed by intention to treat (ITT). The instruments included 7 validated questionnaires which were used to assess chemotherapy complications in the initiation, 4 weeks and 8 weeks after intervention. Dietary intake was measured by 24-h dietary recall at the beginning, week 4 and week 8. Data were analyzed by SPSS software version 24. P-value < 0.05 was considered as statistically significant.

RESULTS

67 breast cancer patients participated in the study. 8 weeks after intervention and adjusting the confounders, the severity of chemotherapy complications including unnormal defecation (P = 0.005) and fatigue (P < 0/001) decreased significantly in the synbiotics group compared to the placebo group. Furthermore, nausea/vomiting (P = 0.015), and anorexia (P < 0.001) were decreased at the end of the study compared to the first visit, but it was not statistically significant compared to the placebo group.

CONCLUSIONS

Synbiotics supplementation during chemotherapy can potentially reduce the severity of fatigue and abnormal defecation. It can help reduce anorexia and nausea/vomiting.

TRIAL REGISTRATION

This study was registered in the Iranian Registry of Clinical Trials (IRCT) (registered code: IRCT20091114002709N56) (date of registration: 5/5/2021). Direct link to the trial page: https://www.irct.ir/trial/54559 .

Expanding CYLD protein in NF-κβ/TNF-α signaling pathway in response to Lactobacillus acidophilus in non-metastatic rectal cancer patients

The CYLD gene is a tumor suppressor, reduced in many cancers. Here, we aimed to investigate CYLD protein level and NF-κβ/TNF-α signaling pathway in rectal cancer patients with Lactobacillus acidophilus (L. acidophilus) consumption. One hundred ten patients with non-metastatic rectal cancer were randomly divided into L. acidophilus probiotic (500 mg, three times daily) and placebo groups for 13 weeks. The expression of CYLD, TNF-α, and NF-κB proteins and the genes involved in the NF-κβ/TNF-α pathway were evaluated using ELISA and qPCR techniques. The survival rate was measured after five years. Unlike the placebo group, the results showed a significant increase in the expression of CYLD protein and tumor suppressor genes, including FOXP3, ROR-γ, Caspase3, GATA3, T-bet, and a considerable decrease in the expression of NF-ҝβ and TNF-α proteins and oncogenes, including STAT3, 4, 5, 6, and SMAD 3, in the probiotic group. A higher overall survival rate was seen after L. acidophilus consumption compared to the placebo group (P < 0.05). L. acidophilus consumption can reduce inflammation factors by affecting CYLD protein and its downstream signaling pathways. A schematic plot of probiotic consumption Effects on the CYLD protein in regulating the NF-ĸβ signaling pathway in colorectal cancer. NF-ĸβ can be activated by canonical and noncanonical pathways, which rely on IκB degradation and p100 processing, respectively. In the canonical NF-κβ pathway, dimmers, such as p65/p50, are maintained in the cytoplasm by interacting with an IκBα protein. The binding of a ligand to a cell-surface receptor activates TRAF2, which triggers an IKK complex, containing -α, -β, -g, which phosphorylates IKK-β. It then phosphorylates IκB-α, leading to K48-ubiquitination and degradation of this protein. The p65/p50 protein freely enters the nucleus to turn on target genes. The non-canonical pathway is primarily involved in p100/RelB activation. It differs from the classical pathway in that only certain receptor signals activate this pathway. It proceeds through an IKK complex that contains two IKK-α subunits but not NEMO. Several materials including peptidoglycan, phorbol, myristate, acetate, and gram-positive bacteria such as probiotics inhibit NF-κB by inducing CYLD. This protein can block the canonical and noncanonical NF-κβ pathways by removing Lys-63 ubiquitinated chains from activated TRAFs, RIP, NEMO, and IKK (α, β, and γ). Moreover, TNF-α induces apoptosis by binding caspase-3 to FADD.

Randomized double-blind, placebo-controlled multicenter phase III study of prevention of irinotecan-induced diarrhea by a probiotic mixture containing Bifidobacterium BB-12®Lactobacillus rhamnosus LGG® in colorectal cancer patients

Background

The incidence of irinotecan-induced diarrhea varies between 60-90%, by which the incidence of severe diarrhea is 20-40%. The objective of this phase III trial was to determine the effectiveness of the probiotic mixture containing Bifidobacterium, BB-12® and Lactobacillus rhamnosus, LGG® in the prophylaxis of irinotecan-induced diarrhea in metastatic colorectal cancer patients due to a reduction in the activity of intestinal beta-D-glucuronidase.

Methods

From March 2016 to May 2022, a total of 242 patients with colorectal cancer starting a new line of irinotecan-based therapy were registered to the study in 11 cancer centers in Slovakia. Patients were randomized in a ratio 1:1 to probiotic formula vs. placebo that was administered for 6 weeks. Each capsule of Probio-Tec® BG-Vcap-6.5 contained 2.7x109 colony-forming units (CFU) of 2 lyophilized probiotic strains Bifidobacterium, BB-12® (50%) and Lactobacillus rhamnosus GG, LGG® (50%).

Results

Administration of probiotics compared to placebo was not associated with a significant reduction of grade 3/4 diarrhea (placebo arm 11.8% vs. probiotic arm 7.9%, p=0.38). Neither the overall incidence of diarrhea (46.2% vs. 41.2%, p=0.51) nor the incidence of enterocolitis (3.4% vs. 0.9%, p=0.37) was different in the placebo vs. probiotic arm. Subgroup analysis revealed that patients with colostomy had higher incidence of any diarrhea and grade 3/4 diarrhea in the placebo arm compared to the probiotic arm (48.5% vs. 22.2%, p=0.06 and 15.2% vs. 0%, p=0.06, respectively). Moreover, patients on probiotic arm had significantly better diarrhea-free survival (HR = 0.41, 95%CI 0.18 - 0.95, p=0.05) and needed less loperamide (p=0.01) compared to patients on placebo arm. We did not observe any infection caused by probiotic strains used in this study.

Conclusion

This study failed to achieve its primary endpoint, and results suggest a lack of benefit of administered probiotic formula for the prevention of irinotecan-induced diarrhea. However, subgroup analysis suggests a possible benefit in patients with colostomy.

Evaluation of effect of consumption of probiotics on the gingival and periodontal health status in children undergoing chemotherapy

Background

Probiotics consist of live microbes. They do not have any adverse effects on health. They provide nutritive benefits to individuals when ingested in adequate quantities. The most common oral infections of the oral cavity are those affecting the periodontal and dental tissues.

Aims and Objectives

1) To evaluate the antimicrobial role of oral probiotics against microorganisms involved in infections of periodontal and dental tissues. 2) To evaluate the state of health of gingival and periodontal tissues of children undergoing chemotherapy after the use of oral probiotics.

Materials and Methods

60 children, between the age group of 3 and 15 years, undergoing chemotherapy were randomly distributed under control and probiotics administered test group for 90 days. The gingival, periodontal, and oral hygiene statuses were evaluated along with their caries activity test. The parameters were measured at 0, 15, 30, 45, 60, 75, and 90 days intervals. Statistical analysis was performed using Statistical Package for the Social Sciences version 18.0.

Results

The oral probiotics consumption significantly reduced the plaque accumulation between days of observation among those in the treatment group (P < 0.05). There was a significant improvement in the gingival and periodontal status in the tested group (P < 0.05). Snyder test was conducted to assess caries activity. Score 1 was found in 10 children, score 2 in eight children. Score 3 was not found in any child under the study group.

Conclusion

The results show that the regular consumption of oral probiotics significantly reduces plaque accumulation, calculus formation, and caries activity among the test group.

Gut microbiota, an emergent target to shape the efficiency of cancer therapy

It is now well-acknowledged that microbiota has a profound influence on both human health and illness. The gut microbiota has recently come to light as a crucial element that influences cancer through a variety of mechanisms. The connections between the microbiome and cancer therapy are further highlighted by a number of preclinical and clinical evidence, suggesting that these complicated interactions may vary by cancer type, treatment, or even by tumor stage. The paradoxical relationship between gut microbiota and cancer therapies is that in some cancers, the gut microbiota may be necessary to maintain therapeutic efficacy, whereas, in other cancers, gut microbiota depletion significantly increases efficacy. Actually, mounting research has shown that the gut microbiota plays a crucial role in regulating the host immune response and boosting the efficacy of anticancer medications like chemotherapy and immunotherapy. Therefore, gut microbiota modulation, which aims to restore gut microbial balance, is a viable technique for cancer prevention and therapy given the expanding understanding of how the gut microbiome regulates treatment response and contributes to carcinogenesis. This review will provide an outline of the gut microbiota's role in health and disease, along with a summary of the most recent research on how it may influence the effectiveness of various anticancer medicines and affect the growth of cancer. This study will next cover the newly developed microbiota-targeting strategies including prebiotics, probiotics, and fecal microbiota transplantation (FMT) to enhance anticancer therapy effectiveness, given its significance.

Synbiotics as Supplemental Therapy for the Alleviation of Chemotherapy-Associated Symptoms in Patients with Solid Tumours

Chemotherapy is still the first line of treatment for most cancer patients. Patients receiving chemotherapy are generally prone to infections, which result in complications, such as sepsis, mucositis, colitis, and diarrhoea. Several nutritional approaches have been trialled to counter the chemotherapy-associated side effects in cancer patients, but none have yet been approved for routine clinical use. One of the approaches to reduce or avoid chemotherapy-associated complications is to restore the gut microbiota. Gut microbiota is essential for the healthy functioning of the immune system, metabolism, and the regulation of other molecular responses in the body. Chemotherapy erodes the mucosal layer of the gastrointestinal tract and results in the loss of gut microbiota. One of the ways to restore the gut microbiota is through the use of probiotics. Probiotics are the ‘good’ bacteria that may provide health benefits if consumed in appropriate amounts. Some studies have highlighted that the consumption of probiotics in combination with prebiotics, known as synbiotics, may provide better health benefits when compared to probiotics alone. This review discusses the different nutritional approaches that have been studied in an attempt to combat chemotherapy-associated side effects in cancer patients with a particular focus on the use of pre-, pro- and synbiotics.

Feed additives of bacterial origin as an immunoprotective or imunostimulating factor

Since January 2006 when using antibiotics as growth promoters in animal feed have been banned scientists are looking for the best resolution to apply alternative substances. Extensive research into the health-promoting properties of probiotics and prebiotics has led to significant interest in the mechanisms of action of the combined administration of these feed additives as a synbiotic. Subsequent research has led to the development of new products. Among the most important health benefits of additives are, inhibiting the growth of pathogenic bacteria in the GI tract, maintenance of homeostasis, treatment of inflammatory bowel diseases, and increase in immunity. Specific immunomodulatory mechanisms of action are not well understood and the effect is not always positive, though there are no reports of adverse effects of these substances found in the literature. For this reason, research is still being conducted on their proper application. However, due to the difficulties of carrying out research on humans, evidence of the beneficial effect of these additives comes mainly from experiments on animals. The objective of the present work was to assess the effect of probiotics, prebiotics, and synbiotics, as well as new additives including postbiotics, proteobiotics, nutribiotics, and pharmabiotics, on specific immunomodulatory mechanisms of action, increase in immunity, the reduction of a broad spectrum of diseases.

The effect of multistrain probiotics on functional constipation in the elderly: a randomized controlled trial

BACKGROUND AND OBJECTIVES

Constipation is one of the most common gastrointestinal conditions, particularly among older individuals. This study aimed to evaluate the efficacy and safety of selected multistrain probiotics on functional constipation and laboratory blood parameters in the elderly living in a nursing home.

SUBJECTS AND METHODS

Sixty participants (42 females and 18 males) aged 77.9 ± 8.84 years with functional constipation, who met the eligibility criteria, completed the study. In a double-blind, placebo-controlled, parallel design, each participant was randomized to receive either the selected probiotic mixture (N = 28) or placebo (N = 32) for 12 weeks as an adjunct to their usual diet and medications. The liquid probiotic formulation containing Bifidobacterium animalis subsp. lactis BLC1, Lactobacillus acidophilus LA3 and Lactobacillus casei BGP93 was tested for the first time.

RESULTS

Supplementation of selected probiotics resulted in a slight but nonsignificant increase in cumulative stool frequency compared with placebo. However, after the 71st day of the treatment, the cumulative number of stools was significantly higher in the probiotic group (P < 0.05) when the influence of laxative was excluded. The trend towards an increase in the difference between the two groups, which began 1 week after the probiotic intervention, pointed out to their prolonged effect. There were no significant dependent or independent effects of treatment and time on most of the 27 laboratory blood parameters tested.

CONCLUSIONS

Multistrain probiotic supplementation was found to be efficacious, safe and well tolerated in the elderly with functional constipation.

Therapeutic approaches to colorectal cancer via strategies based on modulation of gut microbiota

Colorectal cancer (CRC) ranks third in terms of global incidence and second in terms of death toll among malignant tumors. Gut microbiota are involved in the formation, development, and responses to different treatments of CRC. Under normal physiological conditions, intestinal microorganisms protect the intestinal mucosa, resist pathogen invasion, and regulate the proliferation of intestinal mucosal cells via a barrier effect and inhibition of DNA damage. The composition of gut microbiota and the influences of diet, drugs, and gender on the composition of the intestinal flora are important factors in the early detection of CRC and prediction of the results of CRC treatment. Regulation of gut microbiota is one of the most promising new strategies for CRC treatment, and it is essential to clarify the effect of gut microbiota on CRC and its possible mechanisms to facilitate the prevention and treatment of CRC. This review discusses the role of gut microbiota in the pathogenesis of CRC, the potential of gut microbiota as biomarkers for CRC, and therapeutic approaches to CRC based on the regulation of gut microbiota. It might provide new ideas for the use of gut microbiota in the prevention and treatment of CRC in the near future and thus reduce the incidence of CRC.

The potential role of prebiotics, probiotics, and synbiotics in adjuvant cancer therapy especially colorectal cancer

Cancer is a global health issue that is rising swiftly with younger people and an increased number of patients. The role of human microbiota in the pathophysiology of tumors has been paid more and more attention. Microecologics including prebiotics, probiotics, and synbiotics are among the best validated/proven resources for the application of microbiological prophylaxis and therapy. There is strong evidence that microecologics have anti-cancer activity and their potential association with cancer is significant. In this review, we will focus on the role of prebiotics, probiotics, and synbiotics in tumor suppression in maintaining the colon barrier, metabolism, immune regulation, inhibition of host tumor cell proliferation, and epidemiological-based recommendations. Besides, other signs illuminate the role of microecological agents to adjunct the cancer treatment and counter the toxic side effects of cancer drugs. In addition, we will explore their role in chemotherapy, where these probiotics can be used as an adjunct to chemotherapy, counteracting the toxic side effects of chemotherapy drugs to minimize or optimize the therapeutic effect. In the treatment of cancer, we can see the role of prebiotics, probiotics, synbiotics, and their application in cancer patients, and the effectiveness effect can be considered as a clinical benefit. PRACTICAL APPLICATIONS: A large number of studies have shown that microecologics including prebiotics, probiotics, and synbiotics play an important role in regulating intestinal microecology and contribute to the prevention and treatment of cancer, indicating that prebiotics, probiotics, and synbiotics have the potential to be used as microecological modulators in the adjuvant therapy of cancer. However, it is not clear what is the anti-tumor mechanism of these microecologics and how they antagonize the side effects of cancer chemotherapy and protect normal cells. This paper reviews the role of prebiotics, probiotics, and synbiotics in tumor suppression in maintaining the colon barrier, metabolism, immune regulation, and prevention of rapid growth of host cells, as well as their potential role in cancer chemotherapy. This review helps to better understand the relationship between prebiotics, probiotics, and synbiotics with immune regulation, intestinal microecology, metabolic regulation, and cell proliferation and provides strong evidence for their potential application as microecologics in cancer adjuvant therapy.

Influence of Probiotics in Prevention and Treatment of Patients Who Undergo Chemotherapy or/and Radiotherapy and Suffer from Mucositis, Diarrhoea, Constipation, Nausea and Vomiting

The administration of probiotics to patients treated with chemo- and/or radiotherapy is assumed to be beneficial. The aim of this study was to evaluate the effects of probiotic intake on the severity of selected gastrointestinal side effects of chemotherapy and radiotherapy. The searched databases included PubMed, Web of Science, and Scopus from which twenty-one studies were included. Most of them concerned diarrhoea, however, two of the studies examined constipation, another two nausea and vomiting, and eight of the included studies regarded mucositis. The total number of patients equalled 2621. The time of the conducted therapy, the administered species, neoplasm pathology, and adjuvant therapy varied. The outcome was assessed by gathering information about the statistical significance of the improvements. An enhancement was observed in thirteen studies, where probiotics had a significant impact on each of the included chemo- and/or radiotherapy side effects. However, the heterogeneity of the assessed data makes it impossible to state a firm conclusion.

The role of synbiotics in improving inflammatory status in nasopharyngeal carcinoma patients

Nasopharyngeal carcinoma (NPC) is a malignant tumor that grows from the epithelial cells of nasopharynx. NPC has the ability to modify its metabolism and leads the patient to suffer from malnutrition and cachexia, therefore aggravates the occurrence of impaired inflammatory response. Currently, available treatments for NPC are chemotherapy, radiotherapy, or chemoradiotherapy. Despite of its efficacy, these regimens have been known to elicit various inflammation-related side effects including infection, diarrhea, and mucositis. It has long been established that increased activity of inflammatory response is associated to low survival rate in both early and advanced stage of cancer. Furthermore, uncontrolled and dysregulated inflammatory response are significantly correlated with malignant progression of cancer. Considering how pivotal inflammation to malignancy progression, there is a need for effective strategies to modulate inflammatory response. Various strategies have been proposed to improve immune response in NPC patients including dietary supplementation of synbiotics. Synbiotics refers to the manipulation of both probiotics and prebiotics to provide a synergistic benefit to the host by promoting the growth of beneficial bacteria while inhibiting the growth of pathogenic bacteria. There is a growing number of evidences related to the potential of synbiotics in modulating the pro-inflammatory response and improve immune systems in a variety of conditions, including cancer. In this study, we will discuss the immunomodulatory effects of synbiotics in the nasopharyngeal carcinoma occurrences.

Novel targets in rectal cancer by considering lncRNA-miRNA-mRNA network in response to Lactobacillus acidophilus consumption: a randomized clinical trial

We aimed to explore the lncRNA-miR-mRNA network in response to Lactobacillus acidophilus (L. acidophilus) consumption in rectal cancer patients. The candidate miRs were first taken from the GEO and TCGA databases. We constructed the lncRNA-miR-mRNA network using the high-throughput sequencing data. At last, we created a heatmap based on the experimental data to show the possible correlation of the selected targets. The expression levels of selected targets were measured in the samples of 107 rectal cancer patients undergoing placebo and probiotic consumption and 10 noncancerous subjects using Real-Time PCR. Our analysis revealed a group of differentially expressed 12 miRs and 11 lncRNAs, and 12 genes in rectal cancer patients. A significant expression increase of the selected tumor suppressor miRs, lncRNAs, and genes and a substantial expression decrease of the selected oncomiRs, onco-lncRNAs, and oncogenes were obtained after the probiotic consumption compared to the placebo group. There is a strong correlation between some network components, including miR-133b and IGF1 gene, miR-548ac and MSH2 gene, and miR-21 and SMAD4 gene. In rectal cancer patients, L. acidophilus consumption was associated with improved expression of the lncRNA-miR-mRNA network, which may provide novel monitoring and therapeutic approaches.

Gut microbes and muscle function: can probiotics make our muscles stronger?

Evidence suggests that gut microbiota composition and diversity can be a determinant of skeletal muscle metabolism and functionality. This is true in catabolic (sarcopenia and cachexia) or anabolic (exercise or in athletes) situations. As gut microbiota is known to be causal in the development and worsening of metabolic dysregulation phenotypes such as obesity or insulin resistance, it can regulate, at least partially, skeletal muscle mass and function. Skeletal muscles are physiologically far from the gut. Signals generated by the gut due to its interaction with the gut microbiome (microbial metabolites, gut peptides, lipopolysaccharides, and interleukins) constitute links between gut microbiota activity and skeletal muscle and regulate muscle functionality via modulation of systemic/tissue inflammation as well as insulin sensitivity. The probiotics able to limit sarcopenia and cachexia or promote health performances in rodents are mainly lactic acid bacteria and bifidobacteria. In humans, the same bacteria have been tested, but the scarcity of the studies, the variability of the populations, and the difficulty to measure accurately and with high reproducibility muscle mass and function have not allowed to highlight specific strains able to optimize muscle mass and function. Further studies are required on more defined population, in order to design personalized nutrition. For elderly, testing the efficiency of probiotics according to the degree of frailty, nutritional state, or degree of sarcopenia before supplementation is essential. For exercise, selection of probiotics capable to be efficient in recreational and/or elite athletes, resistance, and/or endurance exercise would also require further attention. Ultimately, a combination of strategies capable to optimize muscle functionality, including bacteria (new microbes, bacterial ecosystems, or mix, more prone to colonize a specific gut ecosystem) associated with prebiotics and other 'traditional' supplements known to stimulate muscle anabolism (e.g. proteins), could be the best way to preserve muscle functionality in healthy individuals at all ages or patients.

Microencapsulating Alginate-Based Polymers for Probiotics Delivery Systems and Their Application

Probiotics exhibit many health benefits and a great potential for broad applications in pharmaceutical fields, such as prevention and treatment of gastrointestinal tract diseases (irritable bowel syndrome), prevention and therapy of allergies, certain anticancer effects, and immunomodulation. However, their applications are limited by the low viability and metabolic activity of the probiotics during processing, storage, and delivery in the digestive tract. To overcome the mentioned limitations, probiotic delivery systems have attracted much attention. This review focuses on alginate as a preferred polymer and presents recent advances in alginate-based polymers for probiotic delivery systems. We highlight several alginate-based delivery systems containing various types of probiotics and the physical and chemical modifications with chitosan, cellulose, starch, protein, fish gel, and many other materials to enhance their performance, of which the viability and protective mechanisms are discussed. Withal, various challenges in alginate-based polymers for probiotics delivery systems are traced out, and future directions, specifically on the use of nanomaterials as well as prebiotics, are delineated to further facilitate subsequent researchers in selecting more favorable materials and technology for probiotic delivery.

The Interplay between Tumour Microenvironment Components in Malignant Melanoma

Malignant melanoma has shown an increasing incidence during the last two decades, exhibiting a large spectrum of locations and clinicopathological characteristics. Although current histopathological, biochemical, immunohistochemical, and molecular methods provide a deep insight into its biological behaviour and outcome, melanoma is still an unpredictable disease, with poor outcome. This review of the literature is aimed at updating the knowledge regarding melanoma’s clinicopathological and molecular hallmarks, including its heterogeneity and plasticity, involving cancer stem cells population. A special focus is given on the interplay between different cellular components and their secretion products in melanoma, considering its contribution to tumour progression, invasion, metastasis, recurrences, and resistance to classical therapy. Furthermore, the influences of the specific tumour microenvironment or “inflammasome”, its association with adipose tissue products, including the release of “extracellular vesicles”, and distinct microbiota are currently studied, considering their influences on diagnosis and prognosis. An insight into melanoma’s particular features may reveal new molecular pathways which may be exploited in order to develop innovative therapeutic approaches or tailored therapy.

The Impact of the Microbiome on Resistance to Cancer Treatment with Chemotherapeutic Agents and Immunotherapy

Understanding the mechanisms of resistance to therapy in human cancer cells has become a multifaceted limiting factor to achieving optimal cures in cancer patients. Besides genetic and epigenetic alterations, enhanced DNA damage repair activity, deregulation of cell death, overexpression of transmembrane transporters, and complex interactions within the tumor microenvironment, other mechanisms of cancer treatment resistance have been recently proposed. In this review, we will summarize the preclinical and clinical studies highlighting the critical role of the microbiome in the efficacy of cancer treatment, concerning mainly chemotherapy and immunotherapy with immune checkpoint inhibitors. In addition to involvement in drug metabolism and immune surveillance, the production of microbiota-derived metabolites might represent the link between gut/intratumoral bacteria and response to anticancer therapies. Importantly, an emerging trend of using microbiota modulation by probiotics and fecal microbiota transplantation (FMT) to overcome cancer treatment resistance will be also discussed.

An Update on the Effects of Probiotics on Gastrointestinal Cancers

Because of their increasing prevalence, gastrointestinal (GI) cancers are regarded as an important global health challenge. Microorganisms residing in the human GI tract, termed gut microbiota, encompass a large number of living organisms. The role of the gut in the regulation of the gut-mediated immune responses, metabolism, absorption of micro- and macro-nutrients and essential vitamins, and short-chain fatty acid production, and resistance to pathogens has been extensively investigated. In the past few decades, it has been shown that microbiota imbalance is associated with the susceptibility to various chronic disorders, such as obesity, irritable bowel syndrome, inflammatory bowel disease, asthma, rheumatoid arthritis, psychiatric disorders, and various types of cancer. Emerging evidence has shown that oral administration of various strains of probiotics can protect against cancer development. Furthermore, clinical investigations suggest that probiotic administration in cancer patients decreases the incidence of postoperative inflammation. The present review addresses the efficacy and underlying mechanisms of action of probiotics against GI cancers. The safety of the most commercial probiotic strains has been confirmed, and therefore these strains can be used as adjuvant or neo-adjuvant treatments for cancer prevention and improving the efficacy of therapeutic strategies. Nevertheless, well-designed clinical studies are still needed for a better understanding of the properties and mechanisms of action of probiotic strains in mitigating GI cancer development.

Microbiota, Bacterial Carbonic Anhydrases, and Modulators of Their Activity: Links to Human Diseases?

The involvement of the human microbiome is crucial for different host functions such as protection, metabolism, reproduction, and especially immunity. However, both endogenous and exogenous factors can affect the balance of the microbiota, creating a state of dysbiosis, which can start various gastrointestinal or systemic diseases. The challenge of future medicine is to remodel the intestinal microbiota to bring it back to healthy equilibrium (eubiosis) and, thus, counteract its negative role in the diseases' onset. The shaping of the microbiota is currently practiced in different ways ranging from diet (or use of prebiotics, probiotics, and synbiotics) to phage therapy and antibiotics, including microbiota fecal transplantation. Furthermore, because microbiota modulation is a capillary process, and because many microbiota bacteria (both beneficial and pathogenic) have carbonic anhydrases (specifically the four classes α, β, γ, and ι), we believe that the use of CA inhibitors and activators can open up new therapeutic strategies for many diseases associated with microbial dysbiosis, such as the various gastrointestinal disorders and the same colorectal cancer.

The gut microbiome: what the oncologist ought to know

The gut microbiome (GM) has been implicated in a vast number of human pathologies and has become a focus of oncology research over the past 5 years. The normal gut microbiota imparts specific function in host nutrient metabolism, xenobiotic and drug metabolism, maintenance of structural integrity of the gut mucosal barrier, immunomodulation and protection against pathogens. Strong evidence is emerging to support the effects of the GM on the development of some malignancies but also on responses to cancer therapies, most notably, immune checkpoint inhibition. Tools for manipulating the GM including dietary modification, probiotics and faecal microbiota transfer (FMT) are in development. Current understandings of the many complex interrelationships between the GM, cancer, the immune system, nutrition and medication are ultimately based on a combination of short-term clinical trials and observational studies, paired with an ever-evolving understanding of cancer biology. The next generation of personalised cancer therapies focusses on molecular and phenotypic heterogeneity, tumour evolution and immune status; it is distinctly possible that the GM will become an increasingly central focus amongst them. The aim of this review is to provide clinicians with an overview of microbiome science and our current understanding of the role the GM plays in cancer.

Chemotherapy-Induced Intestinal Microbiota Dysbiosis Impairs Mucosal Homeostasis by Modulating Toll-like Receptor Signaling Pathways

Chemotherapy-induced intestinal mucositis, a painful debilitating condition affecting up to 40–100% of patients undergoing chemotherapy, can reduce the patients’ quality of life, add health care costs and even postpone cancer treatment. In recent years, the relationships between intestinal microbiota dysbiosis and mucositis have drawn much attention in mucositis research. Chemotherapy can shape intestinal microbiota, which, in turn, can aggravate the mucositis through toll-like receptor (TLR) signaling pathways, leading to an increased expression of inflammatory mediators and elevated epithelial cell apoptosis but decreased epithelial cell differentiation and mucosal regeneration. This review summarizes relevant studies related to the relationships of mucositis with chemotherapy regimens, microbiota, TLRs, inflammatory mediators, and intestinal homeostasis, aiming to explore how gut microbiota affects the pathogenesis of mucositis and provides potential new strategies for mucositis alleviation and treatment and development of new therapies.

Recent development in Se-enriched yeast, lactic acid bacteria and bifidobacteria

Endemic selenium (Se) deficiency is a major worldwide nutritional challenge. Organic Se can be synthesized through physical and chemical methods that are conducive to human absorption, but its high production cost and low output cannot meet the actual demand for Se supplementation. Some microbes are known to convert inorganic Se into organic forms of high nutritional value and Se-enriched probiotics are the main representatives. The aim of the present review is to describe the characteristics of Se-enriched yeast, lactic acid bacteria, bifidobacteria and discuss their Se enrichment mechanisms. Se products metabolized by Se-enriched probiotics have been classified, such as Se nanoparticles (SeNPs) and selenoprotein, and their bioactivities have been assessed. The factors affecting the Se enrichment capacity of probiotics and their application in animal feed, food additives, and functional food production have been summarized. Moreover, a brief summary and the development of Se-enriched probiotics, particularly their potential applications in the field of biomedicine have been provided. In conclusion, Se-enriched probiotics not just have a wide range of applications in the food industry but also have great potential for application in the field of biomedicine in the future.

Probiotics supplementation in patients with colorectal cancer: a systematic review of randomized controlled trials

CONTEXT

Colorectal cancer (CRC) is a leading cause of cancer deaths. Recently, much attention has been given to the microbiome and probiotics as preventive and therapeutic approaches to CRC and the mechanisms involved.

OBJECTIVES

To interpret the findings of randomized controlled trials (RCTs) of probiotics relative to patients with CRC and to outline challenges of and future directions for using probiotics in the management and prevention of CRC.

DATA SOURCES

Web of Science, PubMed, ProQuest, Wile, y and Scopus databases were searched systematically from January 17-20, 2020, in accordance with PRISMA guidelines.

STUDY SELECTION

Primacy RCTs that reported the effects of administration to patients with CRC of a probiotic vs a placebo were eligible to be included.

DATA EXTRACTION

The studies were screened and selected independently by 2 authors on the basis of prespecified inclusion and exclusion criteria. The data extraction and risk-of-bias assessment were also performed independently by 2 authors.

RESULTS

A total of 23 RCTs were eligible for inclusion. Probiotics supplementation in patients with CRC improved their quality of life, enhanced gut microbiota diversity, reduced postoperative infection complications, and inhibited pro-inflammatory cytokine production. The use of certain probiotics in patients with CRC also reduced the side effects of chemotherapy, improved the outcomes of surgery, shortened hospital stays, and decreased the risk of death. Bifidobacteria and Lactobacillus were the common probiotics used across all studies.

CONCLUSION

Probiotics have beneficial effects in patients with CRC regardless of the stage of cancer. There is an opportunity for probiotics to be used in mainstream health care as a therapy in the fight against CRC, especially in early stages; however, larger clinical trialsof selected or a cocktail of probiotics are needed to confirm the efficacy, dosage, and interactions with chemotherapeutics agents.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020166865.

Protective effects of Poria cocos and its components against cisplatin-induced intestinal injury

ETHNOPHARMACOLOGICAL RELEVANCE

Poria cocos (Schw.) Wolf (Poria) is a well-known traditional medicinal fungus. It has been considered to possess spleen-invigorating (Jianpi) effects in traditional Chinese medicine, and is used clinically to treat spleen deficiency (Pixu) with symptoms of intestinal disorders such as diarrhea, indigestion, mucositis and weight loss.

THE AIM OF THIS STUDY

To investigate the protective effects of Poria and its three component fractions (Water-soluble polysaccharides, WP; alkali-soluble polysaccharides, AP; triterpene acids, TA) on cisplatin-induced intestinal injury and explore the underlying mechanisms.

MATERIALS AND METHODS

C57BL/6 mice were treated with Poria powder (PP), WP, AP and TA by oral gavage respectively for 13 days, and intraperitoneally injected with 10 mg/kg of cisplatin on day 10 to conduct a cisplatin-induced intestinal injury model. Pathological changes of ileum and colon were examined using H&E staining. The composition of gut microbiota and the alteration of host metabolites were characterized by 16S rDNA amplicon sequencing and UPLC-QTOF-MS/MS based untargeted metabolomics analysis.

RESULTS

PP and WP attenuated the cisplatin-induced ileum and colon injury, and WP alleviated the weight loss and reversed the elevation of IL-2, IL-6 in serum. Both PP and WP could mitigate cisplatin-induced dysbiosis of gut microbiota, in particular PP and WP decreased the abundance of pathogenic bacteria including Proteobacteria, Cyanobacteria, Ruminococcaceae and Helicobacteraceae, while WP promoted the abundance of probiotics, such as Erysipelotrichaceae and Prevotellaceae. Moreover, WP attenuated the cisplatin-induced alteration of metabolic profiles. The levels of potential biomarkers, including xanthine, L-tyrosine, uridine, hypoxanthine, butyrylcarnitine, lysoPC (18:0), linoleic acid, (R)-3-hydroxybutyric acid, D-ribose, thiamine monophosphate, indolelactic acid and plamitic acid, showed significant correlations with intestinal flora.

CONCLUSIONS

PP and WP possess protective effects against cisplatin-induced intestinal injury via potentially regulating the gut microbiota and metabolic profiles.

Dietary Factors Modulating Colorectal Carcinogenesis

The development of colorectal cancer, responsible for 9% of cancer-related deaths, is favored by a combination of genetic and environmental factors. The modification of diet and lifestyle may modify the risk of colorectal cancer (CRC) and prevent neoplasia in up to 50% of cases. The Western diet, characterized by a high intake of fat, red meat and processed meat has emerged as an important contributor. Conversely, a high intake of dietary fiber partially counteracts the unfavorable effects of meat through multiple mechanisms, including reduced intestinal transit time and dilution of carcinogenic compounds. Providing antioxidants (e.g., vitamins C and E) and leading to increased intraluminal production of protective fermentation products, like butyrate, represent other beneficial and useful effects of a fiber-rich diet. Protective effects on the risk of developing colorectal cancer have been also advocated for some specific micronutrients like vitamin D, selenium, and calcium. Diet-induced modifications of the gut microbiota modulate colonic epithelial cell homeostasis and carcinogenesis. This can have, under different conditions, opposite effects on the risk of CRC, through the production of mutagenic and carcinogenic agents or, conversely, of protective compounds. The aim of this review is to summarize the most recent evidence on the role of diet as a potential risk factor for the development of colorectal malignancies, as well as providing possible prevention dietary strategies.

Targeting the gut microbiome: An emerging trend in hematopoietic stem cell transplantation

Mounting evidence has demonstrated the critical role of the gut microbiome in different cancer treatment modalities showing intensive crosstalk between microbiota and the host immune system. In cancer patients receiving hematopoietic stem cell transplantation (HSCT), conditioning regimens including chemotherapy, radiotherapy, and immunosuppressive therapy, as well as antimicrobial prophylaxis, result in intestinal barrier disruption and massive changes in microbiota composition. According to clinical studies, a drastic loss of microbial diversity during HSCT is associated with enhanced pro-inflammatory immune response and an increased risk of transplant-related complications such as graft-versus-host disease (GvHD) and mortality. In this review, we outline the current understanding of the role of microbiota diversity in the patient response to cancer therapies and highlight the impact of changes in the gut microbiome on clinical outcomes in post-HSCT patients. Moreover, the therapeutic implications of microbiota modulation by probiotics, prebiotics, and fecal microbiota transplantation (FMT) in hematologic cancer patients receiving HSCT are discussed.

Milk fermented by Lactobacillus casei CRL431 administered as an immune adjuvant in models of breast cancer and metastasis under chemotherapy

Chemotherapy is the most common treatment for breast cancer and its metastasis; however, it affects the patients' quality of life. Previously, it was demonstrated that milk fermented by Lactobacillus casei CRL431 (probiotic fermented milk (PFM)) exerted benefits against breast cancer metastasis by modulating the immune response in a mouse model. The aim of this work was to evaluate PFM administration on the side effects of capecitabine and on its anti-tumour/anti-metastatic effects. In vitro, 4T1 breast cancer cells were treated with capecitabine in the presence of immune cells' conditioned media from mice administered with PFM. Cell viability was evaluated by MTT assay. In vivo, BALB/c mice (healthy, bearing breast cancer or with potential metastasis) were treated or not with capecitabine and administered with PFM. Blood cell counts, intestinal damages, lung histology and serum cytokines were evaluated. Results showed that capecitabine's toxicity on 4T1 cells was improved by the immune cells from mice that received PFM when the lower dose of capecitabine was evaluated. PFM reduced capecitabine side effects in all the mouse models and decreased intestinal mucositis and mortality. PFM administration to mice under chemotherapy maintained the anti-cancer/anti-metastasis effect of capecitabine with similar or decreased values for serum IL-10 and TNF-α and decreased IL-6, a cytokine related to poor prognosis in advanced cancer patients. In addition, PFM by itself reduced metastasis without side effects and improved the host's immune response. PFM has a potential to be administered as an immune adjuvant in patients under chemotherapy without affecting the treatment. KEY POINTS: • Milk fermented by L. casei CRL431 (PFM) diminished capecitabine side effects. • Capecitabine's toxicity on 4T1 cells was improved by the PFM-stimulated immune cells. • PFM maintained anti-cancer/anti-metastasis effect of capecitabine in mouse models. Graphical abstract.

Exploring the food-gut axis in immunotherapy response of cancer patients

Nowadays, immunotherapy is widely used to treat different cancer types as it boosts the body's natural defenses against the malignancy, with lower risk of adverse events compared to the traditional treatments. The immune system is able to control cancer growth but, unfortunately, many cancers take advantage of immune checkpoints pathways for the immune evasion. An intricate network of factors including tumor, host and environmental variables influence the individual response to immune checkpoints’ inhibitors. Between them, the gut microbiota (GM) has recently gained increasing attention because of its emerging role as a modulator of the immune response. Several studies analyzed the diversities between immunotherapy-sensitive and immunotherapy-resistant cohorts, evidencing that particular GM profiles were closely associated to treatment effect. In addition, other data documented that interventional GM modulation could effectively enhance efficacy and relieve resistance during immunotherapy treatment. Diet represents one of the major GM determinants, and ongoing studies are examining the role of the food-gut axis in immunotherapy treatment. Here, we review recent studies that described how variations of the GM affects patient’s responsivity to anti-cancer immunotherapy and how diet-related factors impact on the GM modulation in cancer, outlining potential future clinical directions of these recent findings.

Gut Microbiome Modulates Response to Cancer Immunotherapy

With the advent of next-generation sequencing approaches, there has been a renaissance in the microbiome field. Microbial taxonomy and function can now be characterized relatively easily and rapidly-no longer mandating complex culturing approaches. With this renaissance, there is now a strong and growing appreciation for the role of the microbiome (referring to microbes and their genomes) in modulating many facets of physiology-including overall immunity. This is particularly true of the gut microbiome, and there is now an evolving body of the literature demonstrating a role for gut microbes in modulating responses to cancer treatment-particularly immunotherapy. Gut microbes can modulate immunity and anti-tumor responses via a number of different interactions, and these will be discussed herein. Additionally, data regarding the impact of gut microbes on cancer immunotherapy response will be discussed, as will strategies to manipulate the microbiome to enhance therapeutic responses. These efforts to date are not completely optimized; however, there is evidence of efficacy though much additional work is needed in this space. Nonetheless, it is clear that the microbiome plays a central role in health and disease, and strategies to manipulate it in cancer and overall precision health are being explored.

The effects of synbiotic supplementation on serum inflammatory markers and edema volume in breast cancer survivors with lymphedema

Breast cancer-related lymphedema (BCRL) is one of the most common complications of breast cancer treatments, which may be exacerbated by obesity. Dysbiosis may negatively impact the management of obesity and lymphedema by increasing inflammation. The objective of this study was to assess the effects of supplementation with synbiotics on inflammatory markers, serum leptin concentration and edema volume in overweight and obese BCRL women following a low-calorie diet (LCD). In a randomized double-blind controlled clinical trial, 88 breast cancer survivors with lymphedema were supplemented once a day for 10 weeks with either a synbiotic or a placebo capsule. Both groups were under a low-calorie diet (LCD). At the end of the study, synbiotic supplementation resulted in a significant reduction in leptin (P=0.003) and TNF-α (P=0.039) between the study groups. Besides, edema volume was significantly reduced within the synbiotic group after the intervention. We did not observe any significant effects of the synbiotic supplementation in hs-CRP, and IL-1β between the study groups (P=0.550, P=0.118 respectively). Conclusively, synbiotic supplementation along with an LCD program in breast cancer survivors with lymphedema had beneficial effects on the concentration of serum inflammatory markers and edema volume.

Search and Selection of Probiotics That Improve Mucositis Symptoms in Oncologic Patients. A Systematic Review

Mucositis is a common and severe adverse effect of radiotherapy and/or chemotherapy treatments applied to oncologic patients. The development of effective therapies and adjuvant treatments to increase their efficacy and reduce adverse effect is a priority in cancer therapy. Probiotics are non-pathogenic live microorganisms that when ingested in adequate amounts can colonize the intestinal tract promoting the restoration of a healthy gut microbiota and contributing to all its functions including the maintenance of the integrity of the mucosa and the modulation of the immune system. In order to check the possible efficacy and safety of these microorganisms to prevent or ameliorate mucositis' symptoms, we have systematically searched the bibliographic databases MEDLINE (via Pubmed), EMBASE, The Cochrane library, Scopus, Web of science, and Latin American and Caribbean Literature in Health of Sciences (LILACS) using the descriptors "Mucositis", "Probiotics", "Neoplasms", "Humans", and "Clinical Trials". After applying our inclusion and exclusion criteria, 15 studies were accepted for review and critical analysis. Our analysis suggests that a combination of Bifidobacterium longum, Lactobacillus acidophilus, Bifidobacterium breve, Bifidobacterium infantis, and Saccharomyces boulardii could be a good combination of probiotics to reduce incident rates of mucositis or ameliorate its symptoms in chemo or radiotherapy treated patients.

Probiotic Supplementation Decreases Chemotherapy-induced Gastrointestinal Side Effects in Patients With Acute Leukemia

INTRODUCTION

In children with acute leukemia, gut microbiota is modified secondary to chemotherapy administration, leading to gastrointestinal side effects. Probiotics are microorganisms that can restore gut microbiota and may help alleviate gastrointestinal symptoms. The aim of this pilot study was to assess the effects of probiotic supplementation on chemotherapy-induced gastrointestinal side effects in children with acute leukemia (AL).

METHODS

In this randomized pilot study, patients under 17 years of age diagnosed with AL who were on remission induction or remission reinduction chemotherapy were randomly assigned to receive probiotic supplementation (a concentration of 5×109 CFU per sachet was administered at a standard dose twice daily, by mouth) or no probiotic supplementation. The primary endpoint was the prevalence of gastrointestinal side effects. Vomiting, nausea, flatulence, dyspepsia, diarrhea, constipation, abdominal pain, and abdominal distention were assessed in both groups.

RESULTS

Gastrointestinal side effects were less prevalent in the probiotic group, and 3 of the 8 gastrointestinal side effects (nausea, vomiting, and abdominal distension) significantly decreased in the probiotic group (P<0.05). We found for diarrhea a relative risk of 0.5 (95% confidence interval [CI], 0.2-1.2; P=0.04); for nausea an RR of 0.5 (95% CI, 0.4-0.8; P=0.04) and for vomiting an RR of 0.4 (95% CI, 0.2-0.9; P=0.04).

CONCLUSIONS

Daily supplementation with Lactobacillus rhamnosus reduced chemotherapy-induced gastrointestinal side effects in children with AL.

Therapeutic bacteria to combat cancer; current advances, challenges, and opportunities

Successful treatment of cancer remains a challenge, due to the unique pathophysiology of solid tumors, and the predictable emergence of resistance. Traditional methods for cancer therapy including radiotherapy, chemotherapy, and immunotherapy all have their own limitations. A novel approach is bacteriotherapy, either used alone, or in combination with conventional methods, has shown a positive effect on regression of tumors and inhibition of metastasis. Bacteria-assisted tumor-targeted therapy used as therapeutic/gene/drug delivery vehicles has great promise in the treatment of tumors. The use of bacteria only, or in combination with conventional methods was found to be effective in some experimental models of cancer (tumor regression and increased survival rate). In this article, we reviewed the major advantages, challenges, and prospective directions for combinations of bacteria with conventional methods for tumor therapy.

Role of diet and gut microbiota on colorectal cancer immunomodulation

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers, and it is characterized by genetic and epigenetic alterations, as well as by inflammatory cell infiltration among malignant and stromal cells. However, this dynamic infiltration can be influenced by the microenvironment to promote tumor proliferation, survival and metastasis or cancer inhibition. In particular, the cancer microenvironment metabolites can regulate the inflammatory cells to induce a chronic inflammatory response that can be a predisposing condition for CRC retention. In addition, some nutritional components might contribute to a chronic inflammatory condition by regulating various immune and inflammatory pathways. Besides that, diet strongly modulates the gut microbiota composition, which has a key role in maintaining gut homeostasis and is associated with the modulation of host inflammatory and immune responses. Therefore, diet has a fundamental role in CRC initiation, progression and prevention. In particular, functional foods such as probiotics, prebiotics and symbiotics can have a potentially positive effect on health beyond basic nutrition and have anti-inflammatory effects. In this review, we discuss the influence of diet on gut microbiota composition, focusing on its role on gut inflammation and immunity. Finally, we describe the potential benefits of using probiotics and prebiotics to modulate the host inflammatory response, as well as its application in CRC prevention and treatment.

Effects of probiotics on chemotherapy in patients with lung cancer

Chemotherapy damages the intestinal mucosa, causing adverse gastrointestinal reactions. Clostridium butyricum (C. butyricum) reduces the incidence of diarrhea in digestive diseases, including inflammatory bowel disease. Therefore, the aim of the present study was to investigate the role of C. butyricum in patients undergoing chemotherapy. A total of 41 participants with lung cancer were enrolled, and divided into the C. butyricum (CB) or placebo group using 1:1 randomization to obtain 20 CB and 21 placebo participants. On the first and last day of the 3-week intervention, blood and stool samples were collected and analyzed. To analyze stool flora, 16S ribosomal RNA sequencing was performed. The incidence of chemotherapy-induced diarrhea was lower in the CB group compared with the placebo group. The lymphocyte count and platelet/lymphocyte ratio (PLR) was markedly altered between the two groups. Neutrophil/lymphocyte ratio (NLR) and PLR decreased within the CB group. At week 3, the lymphocyte/monocyte ratio (LMR) was higher in the CB group compared with the placebo group. Alterations in lymphocyte subsets and immunoglobulin levels were not significantly different. Albumin (ALB) level and weight did not differ significantly between the two groups. At 3 weeks the total flora diversity did not decrease in either group. Phyla in the CB group varied slightly, while the proportion of Firmicutes in the placebo group decreased significantly. No statistically significant difference was observed between the two groups, though the genera producing short-chain fatty acids tended to increase, and the pathogenic genera tended to decrease in the CB group, which was almost the opposite of the observation in the placebo group. Operational taxonomy unit analysis revealed a notable increase in beneficial flora, including the Clostridium and Lactobacillus genera of the CB group, compared with the placebo group. The present study highlighted that C. butyricum reduced chemotherapy-induced diarrhea in patients with lung cancer, reduced the systemic inflammatory response system and encouraged homeostatic maintenance.

Gut Microbiota and Cancer: From Pathogenesis to Therapy

Cancer is a multifactorial pathology and it represents the second leading cause of death worldwide. In the recent years, numerous studies highlighted the dual role of the gut microbiota in preserving host’s health. Gut resident bacteria are able to produce a number of metabolites and bioproducts necessary to protect host’s and gut’s homeostasis. Conversely, several microbiota subpopulations may expand during pathological dysbiosis and therefore produce high levels of toxins capable, in turn, to trigger both inflammation and tumorigenesis. Importantly, gut microbiota can interact with the host either modulating directly the gut epithelium or the immune system. Numerous gut populating bacteria, called probiotics, have been identified as protective against the genesis of tumors. Given their capability of preserving gut homeostasis, probiotics are currently tested to help to fight dysbiosis in cancer patients subjected to chemotherapy and radiotherapy. Most recently, three independent studies show that specific gut resident species may potentiate the positive outcome of anti-cancer immunotherapy. The highly significant studies, uncovering the tight association between gut microbiota and tumorigenesis, as well as gut microbiota and anti-cancer therapy, are here described. The role of the Lactobacillus rhamnosus GG (LGG), as the most studied probiotic model in cancer, is also reported. Overall, according to the findings here summarized, novel strategies integrating probiotics, such as LGG, with conventional anti-cancer therapies are strongly encouraged.