Alcoholic liver disease (ALD), as a global health problem, is mainly caused by liver inflammation. Meanwhile, probiotics have been considered as a potential and promising strategy to prevent and alleviate ALD. This study aimed to investigate the ameliorative effect of pre-intaking with Lactobacillus plantarum J26 (L. plantarum J26) on alcohol-induced liver inflammation, with emphasis on the underlying mechanism for alleviating ALD. The results indicated that L. plantarum J26 could reduce the abundance of Gram-negative pathogenic bacteria by regulating the gut microbiota in mice with alcoholic liver injury, thereby reducing the lipopolysaccharide (LPS) content in the intestine. In addition, L. plantarum J26 could also maintain the intestinal barrier, prevent LPS from crossing the intestinal barrier to correct disorders of the gut–liver axis and then inhibit the activation of Toll-like receptor 4 (TLR4)-mediated MAPK signaling pathway, reducing liver inflammation and restoring liver functions. In conclusion, pre-intake of L. plantarum J26 could alleviate alcohol-induced liver inflammation, which may be closely related to the role of intestinal microbiota in regulating and maintaining the intestinal barrier and then regulating the MAPK signaling pathway.

The disturbance of intestinal microorganisms and the exacerbation of type 2 diabetes (T2D) are mutually influenced. In this study, the effect of exopolysaccharides (EPS) from Lactobacillus plantarum JY039 on the adhesion of Lactobacillus paracasei JY062 was investigated, as well as their preventive efficacy against T2D. The results showed that the EPS isolated from L. plantarum JY039 effectively improved the adhesion rate of L. paracasei JY062 to Caco-2 cells (1.8 times) and promoted the proliferation of L. paracasei JY062. In the mice experiment, EPS, L. paracasei JY062 and their complex altered the structure of the intestinal microbiota, which elevated the proportion of Bifidobacterium, Faecalibaculum, while inversely decreasing the proportion of Firmicutes, Muribaculaceae, Lachnospiraceae and other bacteria involved in energy metabolism (p < 0.01; p < 0.05); enhanced the intestinal barrier function; promoted secretion of the gut hormone peptide YY (PYY) and glucagon-like peptide-1 (GLP-1); and reduced inflammation by balancing pro-inflammatory factors IL-6, TNF-α and anti-inflammatory factor IL-10 (p < 0.01; p < 0.05). These results illustrate that EPS and L. paracasei JY062 have the synbiotic potential to prevent and alleviate T2D.

Probiotics can prevent obesity and related metabolic complications. In our study, the protective effect and molecular mechanism of Lactobacillus rhamnosus JL1 (separated from the feces of healthy infants) on high-fat diet mice were investigated. After 10 weeks of dietary intervention with L. rhamnosus JL1 intervention, the body weight of the JL1 group (23.78 g) was significantly lower than that of the HFD group (26.59 g, p < 0.05) and the liver index was reduced. Serum biochemical analysis showed that the TC, TG and LDL-C contents of JL1 group mice were significantly decreased (p < 0.05). Histological images of the mice livers showed that the degree of lipid action and damage of hepatic cells were improved. L. rhamnosus JL1 activated the AMPK pathway, and reduced the gene expression of PPAR-γ, LXR-α and SREBP-1C. In addition, the protein expression of PPAR-γ and LXR-α were reduced. After dietary intervention with L. rhamnosus JL1, the concentration of acetic acid, propionic acid, and butyric acid were increased significantly, especially the concentration of butyric acid, which was 63.16% higher than that of the HFD group (p < 0.05). In conclusion, this study provided a theoretical reference for the development and application of probiotics derived from healthy infant feces in health products and functional foods.

Ulcerative colitis (UC) is a chronic and recurrent inflammatory bowel disease, and the intestinal barrier is an important line of defense against intestinal disease. Herein, we investigated the effect of Lactobacillus gasseri JM1 at different doses (1 × 10⁶, 1 × 10⁷, 1 × 10⁸ CFU/day) on colitis mice and explored the possible mechanism. The results showed that L. gasseri JM1 alleviated DSS-induced colitis in mice, with reductions in disease activity index (DAI), histological scores and myeloperoxidase activity as well as alleviation of colonic shortening. Furthermore, L. gasseri JM1 regulated the levels of inflammatory cytokines TNF-α, IL-6, IL-1β, and IL-10; restored the expression of Claudin-3, Occludin, ZO-1, and MUC2; and increased the number of goblet cells and acidic mucin. The 16S rDNA sequencing results indicated that intervention with L. gasseri JM1 balanced the gut microbiota structure by elevating the abundance of beneficial bacteria (Oscillospira, Clostridium and Ruminococcus) and decreasing that of harmful bacteria (Shigella and Turicibacter). Meanwhile, the contents of short-chain fatty acids (SCFAs) increased. In conclusion, L. gasseri JM1 could alleviate intestinal barrier damage in colitis mice by modulating the tight junction structures, intestinal mucus layer, inflammatory cytokines, gut microbiota, and SCFAs. It can be considered a potential preventive strategy to alleviate colitis injury.

Probiotics have received wide attention as a potential way to alleviate gastrointestinal (GI) motility disorders. Herein, we investigated the effects of Lacticaseibacillus paracasei JY062, Lactobacillus gasseri JM1, and the probiotic combination at 5 × 10⁹ CFU/mL on mice induced by loperamide and explored the possible underlying mechanisms in GI motility disorder. After two weeks of probiotic intervention, the results indicated that the probiotic combination alleviated GI motility disorder better. It increased the secretion of excitatory GI regulators motilin, gastrin, and 5-hydroxytryptamine (5-HT) and decreased the secretion of the inhibitory GI regulators peptide YY and nitric oxide (NO), except vasoactive intestinal peptide. 5-HT and NO were related to the mRNA expression of 5-HT₄ receptor and nitric oxide synthase, respectively. The intervention of probiotic combination also increased the number of interstitial cells of Cajal and the expression of SCF/c-kit protein. In addition, it also increased the abundance of beneficial bacteria (Lactobacillus, Rikenellaceae, and Clostridiaceae_Clostridium) and improved the contents of short-chain fatty acids in cecum contents of mice. In conclusion, the probiotic combination of L. paracasei JY062 and L. gasseri JM1 has the potential to alleviate GI motility disorders by balancing intestinal homeostasis.