In vitro assessment of horse-isolated strains of Lactobacillus acidophilus and Ligilactobacillus equi species for fecal microbiota modulation in horses.

This research aimed at understanding the potential of certain probiotic strains, specifically Lactobacillus acidophilus and Ligilactobacillus equi, isolated from horses, in modulating the fecal microbiota of these animals. The study found that one strain of Lactobacillus acidophilus resulted in increased microbiota diversity and a higher production of valuable short-chain fatty acids, without leading to negative effects such as acidification or excessive gas production.

Introduction

• Horses, which are hindgut fermenters, rely heavily on their intricate intestinal microbiota (IM) for their digestion process and overall nutrition.
• The IM contributes key enzymes to help break down the complex carbohydrates in the herbivorous diet of horses.
• Imbalances in the IM can cause changes in fermentation patterns, negatively affecting health and increasing disease risk.
• Research in how probiotics can enhance hindgut fermentation and diet digestion in horses is quite limited, especially in the area of using lactobacilli strains derived from horses themselves.

Methods

• The study conducted separate fecal batch fermentations using feces from “Asturcón” horses as inocula mixed individually with two different strains each of Lactobacillus acidophilus and Ligilactobacillus equi, both isolated from the same breed of horses.
• The influence on gut microbiota composition was measured using 16S rRNA gene profiling.
• Metabolic activity, by means of short-chain fatty acids production, was determined through gas chromatography.
• To validate the functionality of the lactobacilli strains, live gas production monitoring was done continuously and pH changes were noted during incubation.

Results and Implications

• The findings revealed that Lactobacillus acidophilus IPLA20127 led to an enhanced IM diversity and raised the relative abundance of the Lactobacillus genus.
• Moreover, it resulted in elevated levels of beneficial short-chain fatty acids like butyric and valeric acid.
• Importantly, this particular strain didn’t trigger acidification or augment gas production, nor led to drastic IM changes, based on the experimental model used.
• The findings underscore the potential use of this strain as a probiotic supplement in horses, with potential benefits to their IM health and digestion.