Bifidobacterium longum, Lactobacillus plantarum and Pediococcus acidilactici Reversed ETEC-Inducing Intestinal...

Area of Science:

• Microbiology
• Immunology
• Gastroenterology

Background:

• Enterotoxigenic Escherichia coli (ETEC) K88 causes significant diarrhea and weight loss in piglets.
• The precise mechanisms by which microecological preparations mitigate ETEC-induced diarrhea are not fully understood.
• Identifying key bacterial strains and their roles in preventing ETEC infection is crucial for developing effective treatments.

Purpose of the Study:

• To investigate the preventative mechanisms of specific probiotic strains and their mixtures against ETEC K88-induced diarrhea in a mouse model.
• To determine the effects of probiotics on intestinal morphology, immune response, and gut microbiota composition.
• To elucidate the impact of probiotics on carbohydrate metabolism pathways in the context of ETEC infection.

Main Methods:

• Thirty-six male mice were randomly assigned to six groups: control, ETEC K88 challenge, and four groups receiving different probiotic treatments (Bifidobacterium longum, Lactobacillus plantarum, Pediococcus acidilactici, or mixed strains) combined with ETEC K88.
• Measurements included body weight, jejunal villus height to crypt depth ratio, serum cytokine levels (IL-1β, IL-6, TNF-α), and mRNA expression of inflammatory and signaling pathway genes (TLR4, MyD88, NF-κB).
• Gut microbiota composition was analyzed using 16S rRNA sequencing, and metabolic pathways were assessed.

Main Results:

• Probiotic treatments significantly alleviated weight loss and restored jejunal villus height to crypt depth ratio.
• Most probiotic strains reduced serum levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α) and downregulated inflammatory gene expression in the jejunum.
• Probiotics rebalanced the gut microbiota, enriching beneficial genera like Bifidobacterium, Lactobacillus, Coriobacteriaceae_UCG-002, Christensenellaceae_R-7_group, and Akkermansia, while counteracting ETEC-induced enrichment of Desulfovibrio.
• Probiotic pre-treatment enhanced starch and sucrose metabolism, galactose and fructose metabolism, mannose metabolism, and ABC transporters.

Conclusions:

• Microecological preparations effectively alleviate ETEC K88-induced diarrhea in mice.
• The protective effects are mediated through modulation of the immune response, restoration of intestinal microbiota homeostasis, and improvement of carbohydrate metabolism.
• Specific probiotic strains, including Lactobacillus plantarum and Pediococcus acidilactici, play significant roles in mitigating ETEC-induced pathology.