Short-chain fatty acid butyrate: A novel shield against chronic gastric ulcer

Postbiotic butyrate: role and its effects for being a potential drug and biomarker to pancreatic cancer

Postbiotics are produced by microbes and have recently gained importance in the field of oncology due to their beneficial effects to the host, effectiveness against cancer cells, and their ability to suppress inflammation. In particular, butyrate dominates over all other postbiotics both in quantity and anticancer properties. Pancreatic cancer (PC), being one of the most malignant and lethal cancers, reported a decreased 5-year survival rate in less than 10% of the patients. PC causes an increased mortality rate due to its inability to be detected at an early stage but still a promising strategy for its diagnosis has not been achieved yet. It is necessary to diagnose Pancreatic cancer before the metastatic progression stage. The available blood biomarkers lack accurate and proficient diagnostic results. Postbiotic butyrate is produced by gut microbiota such as Rhuminococcus and Faecalibacterium it is involved in cell signalling pathways, autophagy, and cell cycle regulation, and reduction in butyrate concentration is associated with the occurrence of pancreatic cancer. The postbiotic butyrate is a potential biomarker that could detect PC at an early stage, before the metastatic progression stage. Thus, this review focused on the gut microbiota butyrate's role in pancreatic cancer and the immuno-suppressive environment, its effects on histone deacetylase and other immune cells, microbes in major butyrate synthesis pathways, current biomarkers in use for Pancreatic Cancer.

Early microbial intervention reshapes phenotypes of newborn Bos taurus through metabolic regulations

BACKGROUND

The rumen of neonatal calves has limited functionality, and establishing intestinal microbiota may play a crucial role in their health and performance. Thus, we aim to explore the temporal colonization of the gut microbiome and the benefits of early microbial transplantation (MT) in newborn calves.

RESULTS

We followed 36 newborn calves for 2 months and found that the composition and ecological interactions of their gut microbiomes likely reached maturity 1 month after birth. Temporal changes in the gut microbiome of newborn calves are widely associated with changes in their physiological statuses, such as growth and fiber digestion. Importantly, we observed that MT reshapes the gut microbiome of newborns by altering the abundance and interaction of Bacteroides species, as well as amino acid pathways, such as arginine biosynthesis. Two-year follow-up of those calves further showed that MT improves their later milk production. Notably, MT improves fiber digestion and antioxidant capacity of newborns while reducing diarrhea. MT also contributes to significant changes in the metabolomic landscape, and with putative causal mediation analysis, we suggest that altered gut microbial composition in newborns may influence physiological status through microbial-derived metabolites.

CONCLUSIONS

Our study provides a metagenomic and metabolomic atlas of the temporal development of the gut microbiome in newborn calves. MT can alter the gut microbiome of newborns, leading to improved physiological status and later milk production. The data may help develop strategies to manipulate the gut microbiota during early life, which may be relevant to the health and production of newborn calves.

Probiotic Supplementation With Saccharomyces boulardii and Enterococcus faecium Improves Gastric Pain and Bloating in Airline Pilots With Chronic Non-atrophic Gastritis: An Open-Label Study

Background Commercial airline pilots (APs) are prone to upper gastrointestinal symptoms, such as epigastric pain and bloating. These issues are often linked to occupational risk factors like irregular diet, sleep disruption, and circadian rhythm disturbance. The use of probiotics to enhance intestinal health is well established, but their efficacy in treating upper gastrointestinal diseases is still debated. This is primarily due to the stomach's small resident microbiota and its low pH, which is inhospitable to most microbes. However, emerging research suggests that specific probiotic strains, such as Enterococcus faecium, can withstand acidic environments. Moreover, certain yeast species, including Saccharomyces boulardii, can survive at a low pH. Consequently, we conducted a preliminary, three-arm, randomized, open-label, dose-finding, four-week study to compare the effects of watchful waiting (WW) with the administration of an oral probiotic supplement containing S. boulardii and E. faecium in APs diagnosed with Helicobacter pylori-negative chronic non-atrophic gastritis (CNG). Methods The study included 39 APs with CNG who were randomized into three groups with a 1:1:1 ratio. The low-dose group (n = 13) received one capsule of the probiotic supplement twice daily, before meals, for four weeks. The high-dose group (n = 13) was administered two capsules of the supplement on the same schedule. The third group (n = 13) underwent WW and served as the control arm. Blinding was maintained for the examining physicians and laboratory staff, but not for the patients. All participants self-rated their experiences of gastric pain and bloating at the beginning and conclusion of the four-week treatment period. Additionally, serum levels of pepsinogen I (PGI) and pepsinogen II (PGII) were measured at these time points. Results Supplementation with probiotics significantly outperformed WW in reducing subjective gastric pain and bloating. This effect was consistent across both tested dosages, with no significant differences observed. However, only high-dose probiotics led to a statistically significant decrease in PGII levels and an increase in the PGI/PGII ratio after the four-week study period, a result not observed with low-dose probiotics. Conclusions Oral administration of S. boulardii and E. faecium demonstrated potential efficacy in reducing gastric pain and bloating symptoms in APs with CNG, as evidenced by statistically significant symptom improvement compared to the control group that did not receive the probiotic supplementation. Notably, high-dose probiotics resulted in a significant increase in the PGI/PGII ratio, indicating potential long-term cytoprotective effects on the gastric mucosa.

Licorice flavonoid alleviates gastric ulcers by producing changes in gut microbiota and promoting mucus cell regeneration

Licorice flavonoid (LF) is the main component of Glycyrrhizae Radix et Rhizoma, a "medicine food homology" herbal medicine, which has anti-digestive ulcer activity, but the mechanism in anti-gastric ulcer (GU) remains to be elucidated. In this study, we manifested that LF increased the viability of human gastric mucosal epithelial (GES-1) cells, attenuated ethanol (EtOH)-induced manifestations, reduced histological injury, suppressed inflammation, and restored gastric mucosal barrier in GU rats. After LF therapy, the EtOH-induced gut dysbiosis was partly modulated, and short-chain fatty acids (SCFAs) like butyric acid, propionic acid, and valeric acid were found in higher concentrations. We discovered that the majority of genera that increased in the GU group had a negative correlation with SCFAs in the intestinal tract. In addition, LF-upregulated SCFAs boosted mucus secretion in the gastric epithelium and the expression of mucoprotein (MUC) 5AC and MUC6, particularly the MUC5AC in the gastric foveola. Moreover, LF triggered the EGFR/ERK signal pathway which promoted gastric mucus cell regeneration. Therefore, the findings indicated that LF could inhibit inflammation, promote mucosal barrier repair and angiogenesis, regulate gut microbiota and SCFA metabolism; more importantly, promote epithelial proliferation via activation of the EGFR/ERK pathway, exerting a protective and regenerative effect on the gastric mucosa.

Gut microbiota-derived short-chain fatty acids regulate gastrointestinal tumor immunity: a novel therapeutic strategy?

Tumor immune microenvironment (TIME), a tumor-derived immune component, is proven to be closely related to the development, metastasis, and recurrence of tumors. Gut microbiota and its fermented-metabolites short-chain fatty acids (SCFAs) play a critical role in maintaining the immune homeostasis of gastrointestinal tumors. Consisting mainly of acetate, propionate, and butyrate, SCFAs can interact with G protein-coupled receptors 43 of T helper 1 cell or restrain histone deacetylases (HDACs) of cytotoxic T lymphocytes to exert immunotherapy effects. Studies have shed light on SCFAs can mediate the differentiation and function of regulatory T cells, as well as cytokine production in TIME. Additionally, SCFAs can alter epigenetic modification of CD8⁺ T cells by inhibiting HDACs to participate in the immune response process. In gastrointestinal tumors, the abundance of SCFAs and their producing bacteria is significantly reduced. Direct supplementation of dietary fiber and probiotics, or fecal microbiota transplantation to change the structure of gut microbiota can both increase the level of SCFAs and inhibit tumor development. The mechanism by which SCFAs modulate the progression of gastrointestinal tumors has been elucidated in this review, aiming to provide prospects for the development of novel immunotherapeutic strategies.

Hypomagnetic Field Exposure Affecting Gut Microbiota, Reactive Oxygen Species Levels, and Colonic Cell Proliferation in Mice

The gut microbiota has been considered one of the key factors in host health, which is influenced by many environmental factors. The geomagnetic field (GMF) represents one of the important environmental conditions for living organisms. Previous studies have shown that the elimination of GMF, the so-called hypomagnetic field (HMF), could affect the physiological functions and resistance to antibiotics of some microorganisms. However, whether long-term HMF exposure could alter the gut microbiota to some extent in mammals remains unclear. Here, we investigated the effects of long-term (8- and 12-week) HMF exposure on the gut microbiota in C57BL/6J mice. Our results clearly showed that 8-week HMF significantly affected the diversity and function of the mouse gut microbiota. Compared with the GMF group, the concentrations of short-chain fatty acids tended to decrease in the HMF group. Immunofluorescence analysis showed that HMF promoted colonic cell proliferation, concomitant with an increased level of reactive oxygen species (ROS). To our knowledge, this is the first in vivo finding that long-term HMF exposure could affect the mouse gut microbiota, ROS levels, and colonic cell proliferation in the colon. Moreover, the changes in gut microbiota can be restored by returning mice to the GMF environment, thus the possible harm to the microbiota caused by HMF exposure can be alleviated. © 2022 Bioelectromagnetics Society.

Proof-of-Principle Study Suggesting Potential Anti-Inflammatory Activity of Butyrate and Propionate in Periodontal Cells

Short-chain fatty acids (SCFAs) are potent immune modulators present in the gingival crevicular fluid. It is therefore likely that SCFAs exert a role in periodontal health and disease. To better understand how SCFAs can module inflammation, we screened acetic acid, propionic acid, and butyric acid for their potential ability to lower the inflammatory response of macrophages, gingival fibroblasts, and oral epithelial cells in vitro. To this end, RAW 264.7 and primary macrophages were exposed to LPSs from Porphyromonas gingivalis (P. gingivalis) with and without the SCFAs. Moreover, gingival fibroblasts and HSC2 oral epithelial cells were exposed to IL1β and TNFα with and without the SCFAs. We report here that butyrate was effective in reducing the lipopolysaccharide (LPS)-induced expression of IL6 and chemokine (C-X-C motif) ligand 2 (CXCL2) in the RAW 264.7 and primary macrophages. Butyrate also reduced the IL1β and TNFα-induced expression of IL8, chemokine (C-X-C motif) ligand 1 (CXCL1), and CXCL2 in gingival fibroblasts. Likewise, butyrate lowered the induced expression of CXCL1 and CXCL2, but not IL8, in HSC2 cells. Butyrate further caused a reduction of p65 nuclear translocation in RAW 264.7 macrophages, gingival fibroblasts, and HSC2 cells. Propionate and acetate partially lowered the inflammatory response in vitro but did not reach the level of significance. These findings suggest that not only macrophages, but also gingival fibroblasts and oral epithelial cells are susceptive to the anti-inflammatory activity of butyrate.