While bovine colostrum is the most common on the market, colostrum from other animals, such as sheep and goats, is increasingly being used in Europe, according to market research platform Grand View Research. Gut health science company Zoe singled out bovine colostrum as a ‘health and wellness fad to avoid.’ A systematic review of studies on the effect of bovine colostrum on gastrointestinal diseases found inconclusive results. Colostrum, despite its clear potential as a functional ingredient, remains controversial, both in terms of animal welfare and in terms of health benefits. Whether any of this will prevent it from succeeding as a functional food remains to be seen.