7 hours ago, sethoflagos said:

I wonder if FODMAP sensitivity arises in part due to the typically impoverished diet of Western industrialised nations. Where of course, most of the limited research in the area will have been done, with all the consequent selection bias that implies.

I think that this is a good point and also a reminder that most food studies are association studies with very limited understanding of underlying mechanisms. There are also trials, which are better controlled but are generally also only limited to measurement of clinical endpoints, without mechanistic insights. This issue also extends to our understanding of the role of the gut microbiota in human health.

As such, these types of studies are frequently are associated with limited reproducibility, which, I assume, will amplify if we look at more diverse populations. Moreover, extrapolation of such data will more likely than not result in predictions that do not turn out to be true.

52 minutes ago, CharonY said:

I think that this is a good point and also a reminder that most food studies are association studies with very limited understanding of underlying mechanisms. There are also trials, which are better controlled but are generally also only limited to measurement of clinical endpoints, without mechanistic insights. This issue also extends to our understanding of the role of the gut microbiota in human health.

As such, these types of studies are frequently are associated with limited reproducibility, which, I assume, will amplify if we look at more diverse populations. Moreover, extrapolation of such data will more likely than not result in predictions that do not turn out to be true.

Yeah, there is a lot of slop, when you have five types of RS, and then also half a dozen types of soluble fiber and insoluble fiber all interacting with the gut colony in various ways. I recently was aware of some friends who were swearing off FODMAPs, as if that was a longterm diet, and I had to warn them that a lot of FODMAP foods are really good for you and you curtail them only temporarily (working with a physician ) to get relief from serious IBS symptoms. After that, the strategy is to work with probiotics and prebiotics and mechanical roughage and vitamins, etc to normalize your intestinal colony and redevelop a tolerance for FODMAPs. I used to work with a food chemist and nutritionist who related an experience treating gut problems in an Alaskan population and finding that vitamin D supplements wrought improvements in people who weren't eating fatty fishes and so were especially deficient (Alaska not being big on sunshine) in a vitamin now linked to a healthy gut microbiome.

That's just one example of another component in the complexity of gut health and where they're only beginning to understand the molecular signaling pathways with vitamin D, the gut barrier, microbiota, and the development of IBD. (Nigerians: you probably have less need to worry about vitamin D...)

17 minutes ago, TheVat said:

(Nigerians: you probably have less need to worry about vitamin D...)

It's an issue in diaspora populations, particularly northern Europe where a dark skin reduces solar vitamin D synthesis between three- and five-fold compared to the white population.

6 minutes ago, sethoflagos said:

It's an issue in diaspora populations, particularly northern Europe where a dark skin reduces solar vitamin D synthesis between three- and five-fold compared to the white population.

Yes, that can he a big adjustment. In my neighbor state of Minnesota, there's a large Somali diaspora and, aside from the overall climatic shock of being in one of the USA's coldest and snowiest locations, an issue with vitamin D absorption. (Generally, my impression is that the places with forbidding winters are often the most welcoming in the US - perhaps because the winters reinforce the idea that we all depend on each other and general good will in order to survive?)

1 hour ago, TheVat said:

Yes, that can he a big adjustment. In my neighbor state of Minnesota, there's a large Somali diaspora and, aside from the overall climatic shock of being in one of the USA's coldest and snowiest locations, an issue with vitamin D absorption. (Generally, my impression is that the places with forbidding winters are often the most welcoming in the US - perhaps because the winters reinforce the idea that we all depend on each other and general good will in order to survive?)

Btw: I couldn't resist sampling the fermented cucumber this afternoon. Delicious! And quite different to the pickled version.

2 hours ago, TheVat said:

eah, there is a lot of slop, when you have five types of RS

And even that is problematic and at best inconsistent. For example, Type I is characterized by accessibility, i.e. starch to which enzymes cannot get to. Type II otoh is based on origin (e.g. raw starch from plant species), forming resistant granules. Type III are generally spontaneously generated precipitated starches with some some-crystalline structres and then IV are or modified starches.

This classification might make sense in food sciences, but in a microbial context it is pretty much meaningless. Within each of these groups you have different chemical compositions, which will be utilized and processed differently by bacteria, for example.