I largely fixed my chronic fatigue by mid-year with the B12 oils, after beginning them in Feb. After this process began I developed severe intolerances to FODMAP foods. At the same time I got a parasitic skin infection from my third world travel - cutaneous leishmaniasis – which was accompanied, as it often is, by boils. I began by going on the low-FODMAP diet – which was effectual for the gut. However after the recommended 2 months on the diet I couldn’t reintroduce FODMAP foods without gut consequences. I bought some Vaalia yogurt, which contains L. rhamnosus – the bacterial strain with the most studies relating to gut-fixing. I cultured some in coconut milk (I don’t do well with dairy), & also cultured a few other strains (either mixed together or separately) to get the needed bacterial diversity that the studies also point to. (For example L. paracasei shirota from Yakult, which has great studies behind it.) Ably helped by @Gondwanaland, I ate all the above quite small quantities, & was fairly quickly able to reintroduce FODMAPs – carefully at first, & now with some abandon. The skin problems stopped too. I’m also quite a lot calmer & less stress-prone, which fits with the theory that psychology begins in the gut. So far so good, but about a month ago the yogurts started giving me headaches, runny nose, severe fatigue, itching eyes, palps & more – histamines! I went down to 1 teaspoonful a day, & even that gave me symptoms sometimes. For the first time I also began to get bad histamine reactions to foods such as beans, alcohol, cold meat, pickled veg. I suspect I’ve had these reactions, mildly, for years. My question is why would they flare up into full-blown symptomatology now? My health in most other respects is much improved. I'm puzzled because histamine response is supposed to improve with improving methylation & gut function - not get worse.