Chickens are the most consumed meat globally, with poultry demand expected to double by 2050. This underscores the urgent need for sustainable production strategies that also ensure positive animal health and welfare outcomes. Microbiota manipulation offers an innovative solution. In natural settings, chickens acquire a highly diverse microbiota from their parents. However, in commercial farms, chicks are isolated from adult birds, resulting in a less diverse microbiota. One result of this low diversity is that it is relatively easy to manipulate the microbiota of chicks in comparison to the microbiota of other species. For example, microbiota transplants from adult chickens to chicks have been highly successful, replicating exposure to adult birds and offering the health, welfare, and productivity benefits associated with a high diversity microbiota. My group employs multi-omics, microbiota transplants, and immune gene knockout models to elucidate the chicken microbiota's role in nutrition and disease resistance. Our long-term goal is to develop on-farm microbiota interventions that sustainably enhance chicken health and productivity. Using metagenomics, we have demonstrated that insights from commercial breeds don't apply to chickens from smallholder flocks in low- and middle-income countries (LMICs), emphasizing the need for targeted agricultural microbiota research in LMICs. We have used multi-omic analyses to identify key microbes and genes involved in fibre fermentation in commercial chickens and identified crucial immune genes affecting microbiota composition using knockout models. Our findings highlight the potential of microbiota interventions to enhance poultry farming in both commercial farms and in smallholder farms.