Sourdough

Sourdough is notable for gluten, histamine, FODMAPs, oligosaccharides and tyramine. Clear on lactose, fructose, sorbitol, sucrose, salicylate, nickel and oxalates.

Yes — sourdough is high in gluten. Sourdough fermentation does NOT make bread gluten-free. It degrades some gluten peptides, but nowhere near enough for coeliac disease: a wheat or rye sourdough remains a gluten-containing food.

Sourdough contains moderate levels of histamine. Sourdough is a live lactic fermentation, and lactic bacteria produce biogenic amines including histamine. Long-fermented breads are commonly flagged in histamine-intolerance guidance, and the longer the rise, the higher the amine load.

Sourdough contains only low levels of FODMAPs. Long sourdough fermentation breaks down much of the fructan content, which is why sourdough breads test far lower in FODMAPs than the flour they are made from. The reduction depends on fermentation time — a short, yeast-accelerated 'sourdough-style' loaf keeps most of its fructans. Monash gives a SERVE THRESHOLD, which is a different object from a content. A threshold answers how much, and for grams per hundred the papers are the source, not the app.

Sourdough contains only low levels of oligosaccharides. Sourdough: same reason as the FODMAP level: the lactic bacteria consume much of the fructan (an oligosaccharide) during a long fermentation. Amounts vary by brand and recipe, so always check the label of the exact product.