The Lab Library

GI & Microbiome

Gut absorption, pancreatic function, and the microbiome — mapped by a few clever markers.

The gastrointestinal markers are unusually good at localising a problem, because where a substance is absorbed or made tells you where things have gone wrong.

B12 is absorbed in the lower gut and folate in the upper gut, so the two read together roughly map where intestinal disease sits — and a high-folate, low-B12 pattern is a classic fingerprint of small-intestinal dysbiosis (an altered microbiome). TLI checks the pancreas's output of digestive enzymes; a low value is the defining test for exocrine pancreatic insufficiency, a treatable cause of weight loss despite a big appetite.

Two things make this panel especially satisfying. First, some of its findings are directly correctable — a low B12 can simply be supplemented while the gut heals. Second, it connects to the emerging science of the microbiome, where a validated dysbiosis index is beginning to put a number on gut bacterial balance. Read together and tracked over time, these markers turn vague, chronic gut trouble into something localisable and manageable.

Parameters in this panel