Total SCFA's

Elevated SCFAs may indicate bacterial overgrowth.

High levels might be due to a very high fibre and/or protein diet, small intestinal bacterial overgrowth, or malabsorption, for whatever reason. Treatment will need to address these issues.

- Low levels may suggest that the diet is low in fibre or there is an imbalance in the gut microflora.

- Low levels of bacteria that produce n-butyrate and propionate have been linked to inflammatory diseases such as ulcerative colitis (n-butyrate) and childhood asthma (propionate).

- Patients with advanced colorectal adenoma have reduced fecal n-butyrate and studies indicate that SCFA may play an important role in protection against colorectal cancer. These SCFA, especially n-butyrate, can act in secondary chemoprevention by slowing growth and triggering apoptosis of colon cancer cells, and in primary prevention by activating drug metabolizing enzymes, reducing the mutation burden of carcinogens.

- Consistent with their role in glucose homeostasis, fecal SCFA are often low when metabolic disease is present. Type 2 diabetes and gout have been associated with reduced abundance of butyrate-producing bacteria.

- Low SCFA levels are associated with gut motility problems. Transit times > 50 hours may lead to reduced fecal SCFA due to enhanced colonic uptake.

- Antibiotics reduce SCFA production and may be the cause of diarrhea.

- Fecal SCFA levels tend to be higher in obese/overweight adults than in those who are lean.

SCFAs are produced from the fermentation of fibre and protein by certain components of the gut microflora. The SCFAs produced from the fermentation of fibre by probiotic bacteria such as Bifidobacteria and Lactobacilli have a range of beneficial effects from serving as a fuel for cells lining the intestine (and the rest of the body) to creating an acidic intestinal environment that is unfavourable to potential pathogens.