On the subject of obese people being more susceptible. There’s evidence now that in some people obesity is as a result of autoimmune problems.
Basically, in some individuals, episodes of food poisoning cause the immune system to attack proteins in the gut lining. This causes problems with gut motility as it can lead to nerve damage. So the gut can’t clear itself.
This leads to either Small Intestinal Bacterial Overgrowth or Intestinal Methanogen Overgrowth ( or in some cases both). The former leads to diarrhoea and weight loss, the latter to constipation and weight gain. Some people alternate between the two. Usually these people are given a diagnosis of IBS, although that is changing. Roughly 70% of people with IBS have either the precursor stage to the autoimmune condition or the autoimmune condition itself. At first the body attacks the food poisoning bugs and produces an antibody (Anti-CdtB) for that, then via repeated episodes of food poisoning and molecular mimicry it can start to mistakenly attack the proteins in the cells of the gut wall- at that point it is an autoimmune condition and a different antibody produced- Anti-Vinculin.
In the case of methanogen overgrowth, methane further slows gut motility and has been shown to increase the amount of calories people can absorb from food. So people can literally be eating the recommended number of calories a day for their height/activity level and still rapidly gain weight.
An autoimmune condition is where the body produces too strong a response to invaders, and it has occurred to me that that type of response could be linked to cytokine storms as they are an immune system over reaction too. Some people have methanogen overgrowth with either the autoimmune condition or it’s precursor though.
It’s very much an emerging field. The research of Drs Pimental, Mathur and Rezaie of Cedars-Sinai in LA is really pioneering.