Milk fats can initiate immune dysfunction that can lead to inflammatory bowel disease (IBD). Concentrated milk fat caused mice to develop IBD at three times the rate (60%) that mice fed a low fat diet or a diet with polyunsaturated fats. IBD correlated with the emergence of a bacteria called Bilophila wadsworthia from nearly undetectable levels to about 6% of the microflora. This class of microbes flourishes when it is in an environment rich in sulfur. Milk fats cause the secretion of bile that is rich in sulfur compounds and this allows B. wadsworthia to flourish and damage the lining of the small intestine and lead to the development of leaky gut syndrome.
It may be possible to alter the balance of gut microflora through dietary manipulation to protect against overgrowth of dangerous microbes.