(1) Background: studies have shown that some patients experience mental deterioration after bariatric surgery. (2) Methods: We examined whether the use of probiotics and improved eating habits can improve the mental health of people who suffered from mood disorders after bariatric surgery. We also analyzed patients’ mental states, eating habits and microbiota. (3) Results: Depressive symptoms were observed in 45% of 200 bariatric patients. After 5 weeks, we noted an improvement in patients’ mental functioning (reduction in BDI and HRSD), but it was not related to the probiotic used. The consumption of vegetables and whole grain cereals increased (DQI-I adequacy), the consumption of simple sugars and SFA decreased (moderation DQI-I), and the consumption of monounsaturated fatty acids increased it. In the feces of patients after RYGB, there was a significantly higher abundance of two members of the Muribaculaceae family, namely Veillonella and Roseburia, while those after SG had more Christensenellaceae R-7 group, Subdoligranulum, Oscillibacter, and UCG-005. (4) Conclusions: the noted differences in the composition of the gut microbiota (RYGB vs. SG) may be one of the determinants of the proper functioning of the gut–brain microbiota axis, although there is currently a need for further research into this topic using a larger group of patients and different probiotic doses.

For decades, metformin has been the drug of first choice in the management of type 2 diabetes. However, approximately 2-13% of patients do not tolerate metformin due to gastrointestinal (GI) side effects. Since metformin influences the gut microbiota, we hypothesized that a multi-strain probiotics supplementation would mitigate the gastrointestinal symptoms associated with metformin usage. This randomized, double-blind, placebo-controlled, single-center, cross-over trial (ProGasMet study) assessed the efficacy of a multi-strain probiotic in 37 patients with metformin intolerance. Patients were randomly allocated (1:1) to receive probiotic (PRO-PLA) or placebo (PLA-PRO) at baseline and, after 12 weeks (period 1), they crossed-over to the other treatment arm (period 2). The primary outcome was the reduction of GI adverse events of metformin. 37 out of 82 eligible patients were enrolled in the final analysis of whom 35 completed the 32 weeks study period and 2 patients resigned at visit 5. Regardless of the treatment arm allocation, while on probiotic supplementation, there was a significant reduction of incidence (for the probiotic period in PRO-PLA/PLA-PRO: P = 0.017/P = 0.054), quantity and severity of nausea (P = 0.016/P = 0.024), frequency (P = 0.009/P = 0.015) and severity (P = 0.019/P = 0.005) of abdominal bloating/pain as well as significant improvement in self-assessed tolerability of metformin (P < 0.01/P = 0.005). Moreover, there was significant reduction of incidence of diarrhea while on probiotic supplementation in PRO-PLA treatment arm (P = 0.036). A multi-strain probiotic diminishes the incidence of gastrointestinal adverse effects in patients with type 2 diabetes and metformin intolerance.

(1) Background: Depressive symptoms often appear after surgical treatment. (2) Methods: We involved 41 adults who underwent bariatric surgery a minimum of 6 months before the study and had the Beck scale ≥12. We analysed patients’ mental state, gut barrier markers, faecal short chain fatty acids, and microbiota. (3) Results: Gut microbiota composition differed significantly among patients undergoing two different types of surgery (F = 1.64, p = 0.00002). Additionally, we discovered an association between short chain fatty acids and the Beck scale (F = 1.22, p = 0.058). The rearrangement of bacterial metabolites may be due to the patients’ use of increased dietary protein, with insufficient intake of products containing vegetable fiber (Diet Quality Index (DQI-I )adequacy 22.55 (±3.46) points). (4) Conclusions: Bariatric surgery affects the gut microbiota, which may play an important role in the development of depressive and gastrointestinal symptoms in patients after bariatric surgery. Low fiber consumption and increased levels of faecal isobutyric acid may lead to intestinal inflammation. There is a need for further research on this topic including a larger sample size.

Keywords: bariatric surgery, sleeve gastrectomy, Roux-en-y gastric bypass, obesity, microbiota, gut-brain axis, beck scale, depression, diet, probiotics

The flow cytometry method (FCM) is a widely renowned practice increasingly used to assess the microbial viability of probiotic products. Additionally, the measurement of water activity (a_w) can be used to confirm the presence of viable cells in probiotic products throughout their shelf lives. The aim of this study was to investigate the correlation between changes in a_w and variations in active fluorescent units (AFU), a unit commonly used in flow cytometry method, during the aging of probiotic products containing freeze-dried bacteria. We controlled the stability of probiotic products for bacterial counts (using ISO 19344 method) and a_w levels in commercially available capsules containing freeze-dried bacteria such as Lactobacillus sp. or combinations of Lactobacillus sp. and Bifidobacterium sp. in standard conditions (25 ± 2 °C and 60% relative humidity) over a period of 24 months. During this time, the bacterial contents decreased by 0.12 Log₁₀ in the single-strain product, by 0.16 Log₁₀ in the two-strain product and by 0.26 Log₁₀ in the multi-strain product. With the increase in a_w, the number of bacteria decreased but the a_w at the end point of the stability study did not exceed 0.15 in each of the three tested products. FCM combined with a_w is a prospective analysis that can be used to assess the stability of probiotic products, both for its ability to detect bacterial viability and for practical (analysis time) and economic reasons.

Background: Irritable Bowel Syndrome (IBS) is a complex disorder characterized by altered gut–brain interactions, with gastrointestinal microbiota and metabolic dysregulation playing key roles in its pathophysiology. Identifying specific metabolic alterations within the colonic mucosa may enhance our understanding of IBS and contribute to improved diagnostic and therapeutic approaches. Methods: This cross-sectional study analyzed the metabolomic profiles of colonic mucosal biopsies from 44 IBS patients assessed with ROME IV criteria and 69 healthy controls undergoing colonoscopy. Untargeted metabolomic profiling was conducted using liquid chromatography–mass spectrometry (LC-MS), and differential metabolite analysis was performed via fold-change calculations and machine learning-based classification. Results: IBS patients exhibited distinct mucosal metabolic profiles, with significantly elevated levels of N-acetylneuraminic acid and 1-palmitoylglycerol, suggesting compromised epithelial integrity and increased gut permeability. In contrast, cis-4-hydroxycyclohexanecarboxylic acid, a metabolite associated with protective mucosal functions, was reduced. Random Forest analysis identified these metabolites as key discriminatory features between IBS and control groups, reinforcing their potential role as biomarkers for IBS-related mucosal alterations. Conclusions: Our study highlights the unique metabolomic signatures of IBS at the mucosal level, emphasizing the role of microbial metabolites in disease pathology. These findings may facilitate the development of novel diagnostic tools and targeted therapeutic strategies, advancing personalized management for IBS patients.