Bacillus indicus is a spore-forming probiotic bacterium increasingly researched as a potential adjunct or alternative to antibiotics, particularly for gut health and infection prevention. Scientific interest stems from its ability to survive the harsh conditions of the gastrointestinal tract and its production of bioactive compounds, including carotenoids and antimicrobial peptides. In vitro and animal studies have demonstrated that Bacillus indicus can inhibit the growth of certain pathogenic bacteria, such as Salmonella, Escherichia coli, and Clostridium difficile, by producing bacteriocins and creating a competitive environment in the gut microbiota.

Some commercial probiotic formulations include Bacillus indicus (often as Bacillus indicus HU36) for its purported ability to outcompete harmful bacteria and enhance gut barrier function. However, human clinical trials are limited, and most evidence comes from laboratory and animal models. There is not yet robust, high-quality clinical data showing that Bacillus indicus can reliably replace antibiotics for the treatment of bacterial infections in humans. Its use is better supported as a complementary approach to support gut microbiome health, especially during or after antibiotic use, rather than as a direct substitute for antibiotics. Overall, the evidence is promising but preliminary, warranting a rating of 2 out of 5 for scientific support as an alternative to antibiotics.