Letter: what gastroenterologists should know about VSL#3

Relevance of organ(s)-on-a-chip systems to the investigation of food-gut microbiota-host interactions

The ever greater understanding of the composition and function of the gut microbiome has provided new opportunities with respect to understanding and treating human disease. However, the models employed for in vitro and in vivo animal studies do not always provide the required insights. As a result, one such alternative in vitro cell culture based system, organ-on-a-chip technology, has recently attracted attention as a means of obtaining data that is representative of responses in humans. Organ-on-a-chip systems are designed to mimic the interactions of different tissue elements that were missing from traditional two-dimensional tissue culture. While they do not traditionally include a microbiota component, organ-on-a-chip systems provide a potentially valuable means of characterising the interactions between the microbiome and human tissues with a view to providing even greater accuracy. From a dietary perspective, these microbiota-organ-on-a-chip combinations can help researchers to predict how the consumption of specific foods and ingredients can impact on human health and disease. We provide an overview of the relevance and interactions of the gut microbiota and the diet in human health, we summarise the components involved in the organ-on-a-chip systems, how these systems have been employed for microbiota based studies and their potential relevance to study the interplay between food-gut microbiota-host interactions.

Modulation of Stem Cell Progeny by Probiotics during Regeneration of Gastric Mucosal Erosions

Patients with gastric mucosal erosions are predisposed to chronic gastritis, ulcer or even cancer. The repair of mucosal erosions involves several events including proliferation of gastric epithelial stem cells. The aim of this study was to investigate the effects of the probiotic mixture of De Simone Formulation on gastric epithelial stem cell lineages in mouse models of gastric mucosal erosions. Gastric erosions were induced by a single oral gavage of 80% ethanol containing 15 mg/mL acetylsalicylic acid (5 mL/kg) following a daily dose of probiotic mixture (5 mg/day/mouse) for 10 days. In another protocol, erosions were induced by a daily gavage of acetylsalicylic acid (400 mg/kg/day/mouse) for 5 days before or after daily administration of probiotic mixture for 5 days. Control mice received water gavage for 10 days. All mice were injected with bromodeoxyuridine two hours before sacrifice to label S-phase cells. The stomachs of all mice were processed for histological examination, lectin binding, and immunohistochemical analysis. The results reveal that mice that received probiotics before or after the induction of erosion showed a decrease in erosion index with an increase in gastric epithelial stem/progenitor cell proliferation and enhanced production of mucus, trefoil factors, and ghrelin by mucous and enteroendocrine cell lineages. These mice also showed restoration of the amount of H⁺,K⁺-ATPase and pepsinogen involved in the production of the harsh acidic environment by parietal and chief cell lineages. In conclusion, this study demonstrates the beneficial effects of probiotics against gastric mucosal erosion and highlights the involvement and modulation of proliferative stem cells and their multiple glandular epithelial cell lineages.

Prevention of Severe Intestinal Barrier Dysfunction Through a Single-Species Probiotics is Associated With the Activation of Microbiome-Mediated Glutamate-Glutamine Biosynthesis

INTRODUCTION

Intra-abdominal hypertension (IAH), the leading complication in the intensive care unit, significantly disturbs the gut microbial composition by decreasing the relative abundance of Lactobacillus and increasing the relative abundance of opportunistic infectious bacteria.

METHODS

To evaluate the preventative effect of Lactobacillus-based probiotics on IAH-induced intestinal barrier damages, a single-species probiotics (L92) and a multispecies probiotics (VSL#3) were introduced orally to Sprague-Dawley rats for 7 days before inducing IAH. The intestinal histology and permeability to macromolecules (fluoresceine isothiocyanate, FITC-dextran, N = 8 for each group), the parameters of immunomodulatory and oxidative responses [monocyte chemotactic protein 1 (MCP-1), interleukin-1β (IL-1β), interleukin-4 (IL-4), interleukin-10 (IL-10), malonaldehyde, glutathione peroxidase (GSH- Px), catalase (CAT), and superoxide dismutase; N = 4 for each group], and the microbiome profiling (N = 4 for each group) were analyzed.

RESULTS

Seven-day pretreatments of L92 significantly alleviated the IAH-induced increase in intestinal permeability to FITC-dextran and histological damage (P  < 0.0001), accompanied with the suppression of inflammatory and oxidative activation. The increase of MCP-1 and IL-1β was significantly inhibited (P  < 0.05); the anti-inflammatory cytokines, IL-4, and IL-10 were maintained at high levels; and the suppression of CAT (P  <  0.05) was significantly reversed when pretreated with L92. On the contrary, no significant protective effects were observed in the VSL#3-pretreated group. Among the 84 identified species, 260 MetaCyc pathways, and 217 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, the protective effects of L92 were correlated with an increased relative abundance of Bacteroides finegoldii, Odoribacter splanchnicus, and the global activation of amino acid biosynthesis pathways, especially the glutamate-glutamine biosynthesis pathway.

CONCLUSIONS

Seven-day pretreatment with a single-species probiotics can prevent IAH-induced severe intestinal barrier dysfunction, potentially through microbial modulation.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on pouchitis in ulcerative colitis. Part 2: Treatment

Pouchitis treatment is a complex entity that requires a close medical and surgical relationship. The elective treatment for acute pouchitis is antibiotics. After a first episode of pouchitis it is recommended prophylaxis therapy with a probiotic mix, nevertheless it is not clear the use of this formulation for preventing a first episode of pouchitis after surgery. First-line treatment for chronic pouchitis is an antibiotic combination. The next step in treatment should be oral budesonide. Selected cases of severe, chronic refractory pouchitis may benefit from biologic agents, and anti-TNF α should be recommended as the first option, leaving the new biologicals for multi-refractory patients. Permanent ileostomy may be an option in severe refractory cases to medical treatment.

Probiotics Upregulate Trefoil Factors and Downregulate Pepsinogen in the Mouse Stomach

Probiotics are used in the management of some gastrointestinal diseases. However, little is known about their effects on normal gastric epithelial biology. The aim of this study was to explore how the probiotic mixture VSL#3 affects gastric cell lineages in mice with a special focus on protective and aggressive factors. Weight-matching littermate male mice (n = 14) were divided into treated and control pairs. The treated mice received VSL#3 (5 mg/day/mouse) by gastric gavage for 10 days. Control mice received only the vehicle. Food consumption and bodyweight were monitored. All mice were injected intraperitoneally with bromodeoxyuridine (120 mg/Kg bodyweight) two hours before sacrificed to label S-phase cells. Stomach tissues were processed for lectin- and immunohistochemical examination. ImageJ software was used to quantify immunolabeled gastric epithelial cells. Real-time quantitative polymerase chain reaction was used to provide relative changes in expression of gastric cell lineages specific genes. Results revealed that treated mice acquired (i) increased production of mucus, trefoil factor (TFF) 1 and TFF2, (ii) decreased production of pepsinogen, and (iii) increased ghrelin-secreting cells. No significant changes were observed in bodyweight, food consumption, cell proliferation, or parietal cells. Therefore, VSL#3 administration amplifies specific cell types specialized in the protection of the gastric epithelium.