What are Putrefactive Short Chain Fatty Acids (SCFAs)? High and low values | Lab results explained

Valerate, isovalerate and isobutyrate constitute the putrefactive short chain fatty acids (SCFAs).

Valerate, isovalerate and isobutyrate are produced exclusively by fermentation of protein. These SCFAs are putrefactive, and suggest underlying protein maldigestion, malabsorption, or BOSI.

Higher levels:

Elevated levels result from bacterial fermentation of undigested protein.

Elevated levels of these three SCFAs result from anaerobic bacterial fermentation of polypeptides and amino acids, and suggest hypochlorhydria, exocrine pancreatic insufficiency, and/or protein malabsorption.

Are elevated levels of putrefactive SCFAs always due to maldigestion or malabsorption?

No. Other possible causes include:

  • Bacterial overgrowth in the small intestine (BOSI)— proteins may be fermented before they are fully digested. Look for elevated levels of Beneficial SCFAs and n-butyrate.
  • Gastrointestinal disease— due to the fermentation of blood or mucosal cells delivered to the colon.
  • Rapid transit time— results in too little time for digestion and absorption of dietary peptides and amino acids.

Signs, symptoms, and other laboratory abnormalities may help to suggest contributing factors:

  • Hypochlorhydria—Possible positive Helicobacter pylori antigen, dyspepsia, or B12 insufficiency.
  • Pancreatic insufficiency—Low level of pancreatic elastase or chymotrypsin, possible abdominal discomfort or bloating after eating.
  • Malabsorption—Food in the stool, greasy stools, difficulty gaining weight, gluten intolerance, etc.
  • Bacterial Overgrowth of the Small Intestine (BOSI)—Elevated Total SCFAs and n-butyrate, possible history of hypochlorhydria or bowel stasis, possible gas and post-prandial bloating. Consider a breath test for BOSI.
  • Gastrointestinal disease—Positive fecal occult blood, possible mucus in the stool, signs and symptoms of various disorders.

Treatment should be aimed at the underlying cause:

  • Betaine HCl with pepsin, and/or digestive enzymes
  • Eradication of H. pylori infection
  • Treatment for BOSI

Other testing to consider:

  • Bacterial Overgrowth of the Small Intestine Breath test – consider if Beneficial SCFAs and n-butyrate are also elevated
  • Helicobacter pylori stool antigen test



Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you. 

The information on is NOT intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice.

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