A researcher is studying the effects of a high-sugar diet on the human gut microbiome. After several weeks, they observe a significant reduction in microbial diversity and an increase in harmful bacteria. Based on your understanding of the healthy human microbiome, what can be inferred about the implications of these changes for human health?

A lower diversity in the gut means fewer different microbes are present to carry out healthy functions such as digesting food, producing vitamins, and protecting against pathogens. When harmful bacteria become more common, they can overgrow and release toxins that irritate the gut lining and trigger inflammation. This imbalance can weaken the immune system, increase the risk of digestive problems, and is linked to conditions like obesity, diabetes, and inflammatory bowel disease. For example, if someone consumes a lot of sugar, their gut may favor bacteria that thrive on sugar, crowding out beneficial species that help regulate metabolism. Thus, a high‑sugar diet that reduces diversity and boosts harmful microbes can compromise overall health and raise disease risk.