Inulin Degradation (FOS)

This marker evaluates the genetic capacity of your microbiome to digest Inulin and Fructooligosaccharides (FOS). These soluble fibers, naturally present in foods like garlic, onion, leek, asparagus, and artichoke, are nature's "star prebiotics." A high degradation capacity means your flora transforms these foods into butyrate; a low capacity explains why these same foods cause you severe gas and bloating (FODMAP sensitivity).

Inulin and FOS are long chains composed almost exclusively of fructose molecules. Your own human digestive enzymes are completely incapable of breaking the bonds that link these molecules, so they travel intact through your stomach and small intestine until they reach the colon. Upon reaching the large intestine, two things can happen:

• If you have the right bacteria (e.g., Bifidobacteria): These possess specialized enzymes that slowly "cut" the inulin, releasing energy in a controlled manner and producing short-chain fatty acids (like butyrate and acetate) with hardly any gas production.
• If you lack the right bacteria: The inulin is left at the mercy of opportunistic or rapid fermentation bacteria. These bacteria consume the inulin all at once, generating an explosion of gases (hydrogen and carbon dioxide) that distends the intestine, causing pain, cramps, and flatulence.

The efficiency with which your ecosystem manages these fibers determines your digestive tolerance to many of the healthiest foods in the Mediterranean diet:

• FODMAP Tolerance (Irritable Bowel Syndrome): The "O" in FODMAP stands for Oligosaccharides (which includes FOS and inulin). A low bacterial capacity to orderly degrade inulin is one of the main molecular causes of chronic bloating in IBS patients.
• Bifidogenic Effect: Inulin is the preferred substrate par excellence for Bifidobacteria and Faecalibacterium prausnitzii. Good degradation allows these protective species to flourish, displacing pathogens and reducing intestinal inflammation.
• Mineral Absorption: The correct fermentation of inulin and FOS slightly acidifies the colon environment (lowers the pH). It has been clinically proven that this increases the solubility and, therefore, the absorption of calcium and magnesium by 20%, protecting bone density.

The Inulin and FOS Degradation Capacity is calculated by analyzing the presence of genes encoding for the enzymes exo-inulinase and endo-inulinase, as well as specific fructooligosaccharide transporters (glycoside hydrolase families such as GH32). The most relevant taxa equipped with the GH32 arsenal in the human gut include the genus Bifidobacterium (particularly B. longum and B. adolescentis), as well as certain strains of Lactobacillus and Bacteroides.

Adequate capacity indicates that you can (and should) generously consume garlic, onions, and artichokes to maximize your immune health. Low capacity suggests that you should apply culinary processing strategies (such as infusing garlic in oil instead of eating it raw) or follow a temporary low-FODMAP diet, reintroducing inulin in progressive micro-doses to cultivate your tolerance without overwhelming your system.