(3) Akkermansia is a potential probiotic that is unable to break down glucomannan but can utilize monosaccharides from the breakdown of mucin and glucomannan and break down mucin O-glycans, promoting the growth of mucin-associated bacteria such as butyrate-producing clostridia. In humans, many studies have shown a negative correlation between the abundance of Akkermansia and overweight, obesity, untreated type 2 diabetes, or hypertension [120,121,122,123,124]. The gene discussed is MUC5AC; the disease is obesity due to melanocortin 4 receptor deficiency.