Gut microbes in chickens can be reprogrammed with low-protein diets to boost health and cut pollution.

Farmers want to feed poultry lower-protein feeds to cut costs and emissions, but birds need enough nutrients to stay healthy and grow well. Researchers reviewed studies to see how the gut microbiome—the collection of bacteria and other microbes living in the birds' intestines—reacts to low-protein diets and restricted amounts of lysine, an essential amino acid. When birds eat less protein, their gut bacteria switch to digesting plant fibers instead of protein. Helpful microbes like Ruminococcaceae multiply, while harmful bacteria drop along with toxic waste like ammonia. Limiting lysine forces bacteria to manage nitrogen tightly and alters the fatty acids they produce. These microbial shifts trigger internal bird sensors that redirect nutrients toward immunity and efficient feed use. Overall, these diet-driven changes alter bird genetics and body defense systems, pointing to custom probiotic mixes that can keep flocks healthy without antibiotics.

Why it matters

Poultry farming uses a lot of protein feed, which is expensive and pollutes. This review shows that carefully restricting protein and the amino acid lysine can shift gut bacteria in ways that improve feed efficiency, reduce toxic waste, and even strengthen immunity. That means cheaper, cleaner chicken production without antibiotics.

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