I think most "dense" foods can do that, probably due to changes in microbiome and overgrowth of some fungal stuff. They probably use up / "destroy" thiamine like many fungi do. Lonsdale's "thiamine paradox" fits well there - adding more thiamine feeds more fungi so person gets worse, not better. And according to Lonsdale its a good sign. With the dose high enough improvements start appearing in a month or so and gradually problem resolves. Dose is critical according to him, and low doses might not be sufficient. To me it sounds like with doses high enough some thiamine makes it through fungal/archaea antithiamine action, proper gut flora starts to grow and fight back. Though many people (me inducing) seem to be unable to push through "thiamine paradox" and if this model is right there can be other things, not just high dose thiamine, which could help in resolving all this.Interesting ideas. I'm not sure how much we can extrapolate from these studies but grain feeding in cows seems to reliably induce thiamine deficiency through several mechanism = high lactate (Thiamine status, metabolism and application in dairy cows: a review - PubMed):
"As the co-enzyme of pyruvate dehydrogenase and α-ketoglutarate dehydrogenase, thiamine plays a critical role in carbohydrate metabolism in dairy cows. Apart from feedstuff, microbial thiamine synthesis in the rumen is the main source for dairy cows. However, the amount of ruminal thiamine synthesis, which is influenced by dietary N levels and forage to concentrate ratio, varies greatly. Notably, when dairy cows are overfed high-grain diets, subacute ruminal acidosis (SARA) occurs and results in thiamine deficiency. Thiamine deficiency is characterised by decreased ruminal and blood thiamine concentrations and an increased blood thiamine pyrophosphate effect to >45 %. Thiamine deficiency caused by SARA is mainly related to the increased thiamine requirement during high grain feeding, decreased bacterial thiamine synthesis in the rumen, increased thiamine degradation by thiaminase, and decreased thiamine absorption by transporters. Interestingly, thiamine deficiency can be reversed by exogenous thiamine supplementation in the diet. Besides, thiamine supplementation has beneficial effects in dairy cows, such as increased milk and component production and attenuated SARA by improving rumen fermentation, balancing bacterial community and alleviating inflammatory response in the ruminal epithelium."
Does the same thing happen in humans who eat too much grain/starch?