New insights into the links between anti-diabetes drugs and gut microbiota

Gut Microbiota and Nutrition: Strategies for the Prevention and Treatment of Type 2 Diabetes

The prevalence of diabetes has increased in last decades worldwide and is expected to continue to do so in the coming years, reaching alarming figures. Evidence have shown that patients with type 2 diabetes (T2D) have intestinal microbial dysbiosis. Moreover, several mechanisms link the microbiota with the appearance of insulin resistance and diabetes. Diet is a crucial factor related to changes in the composition, diversity, and activity of gut microbiota (GM). In this review, the current and future possibilities of nutrient-GM interactions as a strategy to alleviate T2D are discussed, as well as the mechanisms related to decreased low-grade inflammation and insulin resistance. A bibliographic search of clinical trials in Pubmed, Web of Science, and Scopus was carried out, using the terms "gut microbiota, diet and diabetes." The data analyzed in this review support the idea that dietary interventions targeting changes in the microbiota, including the use of prebiotics and probiotics, can improve glycemic parameters. However, these strategies should be individualized taking into account other internal and external factors. Advances in the understanding of the role of the microbiota in the development of metabolic diseases such as T2D, and its translation into a therapeutic approach for the management of diabetes, are necessary to allow a comprehensive approach.

Therapeutic effects of microecological agents combined with metformin in type 2 diabetes mellitus with irritable bowel syndrome

BACKGROUND

In recent years, the role of intestinal flora in the occurrence and progression of irritable bowel syndrome (IBS) has been gradually recognized, and, as recommended agents for the treatment of IBS, probiotics, which can promote intestinal motility and correct and maintain the balance of flora, have been proven effective in the treatment of gastrointestinal diseases.

AIM

To investigate the therapeutic effects of microecological agents combined with metformin in patients with type 2 diabetes mellitus (T2DM) with IBS and their modulatory effect on the intestinal flora and the Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD8)/nuclear factor-κB (NF-κB) signaling pathway.

METHODS

Two hundred patients with T2DM with IBS treated at our hospital from August 2018 to August 2022 were selected and randomly divided into either a control group or an observation group, with 100 cases in each group. The control group was treated with metformin alone, and the observation group was treated with microecological agents combined with metformin. Intestinal sensitivity, intestinal flora (Lactobacillus, Bifidobacterium, Escherichia coli, and Enterococcus faecalis), short-chain fatty acids (SCFAs), blood glucose levels [fasting blood glucose (FPG), glycosylated hemoglobin (HbA1c), and 2-hour postprandial glucose (2hPG)], and serum levels of TLR4/MyD88/NF-κB signaling pathway-related proteins were compared between the two groups before and after treatment. The incidence of adverse effects was recorded.

RESULTS

After 4 wk and 8 wk of treatment, the numbers of Lactobacillus and Bifidobacterium were higher, and the numbers of E. coli and Enterococcus faecalis, intestinal sensitivity, and serum MyD88, TLR4, and NF-κBp65 levels were lower in the observation group than in the control group (P < 0.05). After 8 wk of treatment, the levels of butyric acid and total SCFAs were higher, and the levels of FPG, HbA1c, and 2hPG were lower in the observation group than in the control group (P < 0.05). The incidence of adverse reactions did not differ significantly between the observation group (9.00%) and the control group (14.00%).

CONCLUSION

Microecological agents combined with metformin can effectively reduce intestinal sensitivity, alleviate gastrointestinal symptoms, and enhance glucose control in patients with T2DM with IBS, which may be related to their ability to correct flora dysbiosis, regulate intestinal flora metabolites, and modulate the TLR4/MyD88/NF-κB signaling pathway by increasing the abundance of probiotics.

High Fructose Causes More Prominent Liver Steatohepatitis with Leaky Gut Similar to High Glucose Administration in Mice and Attenuation by Lactiplantibacillus plantarum dfa1

High-sugar diet-induced prediabetes and obesity are a global current problem that can be the result of glucose or fructose. However, a head-to-head comparison between both sugars on health impact is still lacking, and Lactiplantibacillus plantarum dfa1 has never been tested, and has recently been isolated from healthy volunteers. The mice were administered with the high glucose or fructose preparation in standard mouse chaw with or without L. plantarum dfa1 gavage, on alternate days, and in vitro experiments were performed using enterocyte cell lines (Caco2) and hepatocytes (HepG2). After 12 weeks of experiments, both glucose and fructose induced a similar severity of obesity (weight gain, lipid profiles, and fat deposition at several sites) and prediabetes condition (fasting glucose, insulin, oral glucose tolerance test, and Homeostatic Model Assessment for Insulin Resistance (HOMA score)). However, fructose administration induced more severe liver damage (serum alanine transaminase, liver weight, histology score, fat components, and oxidative stress) than the glucose group, while glucose caused more prominent intestinal permeability damage (FITC-dextran assay) and serum cytokines (TNF-α, IL-6, and IL-10) compared to the fructose group. Interestingly, all of these parameters were attenuated by L. plantarum dfa1 administration. Because there was a subtle change in the analysis of the fecal microbiome of mice with glucose or fructose administration compared to control mice, the probiotics altered only some microbiome parameters (Chao1 and Lactobacilli abundance). For in vitro experiments, glucose induced more damage to high-dose lipopolysaccharide (LPS) (1 µg/mL) to enterocytes (Caco2 cell) than fructose, as indicated by transepithelial electrical resistance (TEER), supernatant cytokines (TNF-α and IL-8), and glycolysis capacity (by extracellular flux analysis). Meanwhile, both glucose and fructose similarly facilitated LPS injury in hepatocytes (HepG2 cell) as evaluated by supernatant cytokines (TNF-α, IL-6, and IL-10) and extracellular flux analysis. In conclusion, glucose possibly induced a more severe intestinal injury (perhaps due to LPS-glucose synergy) and fructose caused a more prominent liver injury (possibly due to liver fructose metabolism), despite a similar effect on obesity and prediabetes. Prevention of obesity and prediabetes with probiotics was encouraged.