Article Sharing | Host-Microbiota Interactions in Domestic Pigs: The Roles of Prebiotics and Probiotics Ⅱ

Host-Microbiota Interactions in Domestic Pigs: The Roles of Prebiotics and Probiotics Ⅱ

Many earlier studies have found that Lactobacillus is one of the main types of bacteria in pig guts. No matter the pig's age, these bacteria make up about 15% of the gut samples when looking at their 16S rRNA gene sequences. Lactobacillus lives in both the upper and lower parts of the pig's digestive tract and starts to settle there soon after birth.

Giving pigs probiotic Lactobacillus mainly helps improve their overall health, growth performance, and farm productivity. These bacteria can also stop harmful microbes that threaten the host's health. The process of using lactic acid for nutrition is a key way the gut works in mammals. In pigs, more Lactobacillus in the cecum is directly linked to better feed efficiency.

Recent studies also show that certain Lactobacillus strains—specifically L. reuteri  ZLR003 and *L. salivarius* ZLS006—can improve daily weight gain, feed conversion, and nitrogen digestion in growing pigs. They also help lower levels of total cholesterol, certain liver enzymes (ALT and AST), blood urea nitrogen, and haptoglobin in the blood.

As several studies have shown, feeding pigs Lactobacillus can improve meat quality. For example, Lactobacillus plantarum ZJ316, a potential probiotic taken from piglet feces, has good effects on newly weaned piglets. Most notably, it improves some meat quality measures, helps increase villus height in the gut, and seems to stop the growth of harmful bacteria.

Also, adding a probiotic with Weissella to the diet of weaned piglets can raise the amount of certain healthy fats (monounsaturated and polyunsaturated fatty acids) in muscle. This suggests probiotics could help improve the fat content of pork. Additionally, studies on L. jensenii TL2937 show that adding this immune-friendly strain to piglet feed can reduce toughness while improving juiciness and taste, and reducing backfat thickness.

In pigs fed a high-calcium diet, Lactobacillus in the stomach helped increase phosphorus content by 1.4 times.

Because individual pigs vary so much in growth and feed efficiency on commercial farms, it's hard to accurately measure how probiotics affect gut health. Large-scale experiments are needed to fully understand these effects. However, so far, most controlled studies (see Table 1) have focused on how feed additives impact digestive health, including many immune-related measures.

Table 1 Microbiome Outcomes from Studies on Pigs Exposed to Dietary and Environmental Modulations

Table 1 highlights studies in pigs where dietary and environmental conditions were controlled to determine their correlation with changes in the gut microbiota and the subsequent effects on immune responses.