I’m not going to pretend to be an expert here, but I remember a study that found gut bacteria composition predicted whether or not an individual was chocolate-craving or not in individuals eating identical diets: https://pubmed.ncbi.nlm.nih.gov/17929959

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Aurornis 2 hours ago | parent | next [-]

You have to be careful with microbiome research because it’s a buzzword that gets crammed into a lot of research papers to imply something bigger. This is a single paper from Nestle Research Center (yes that Nestle) from 2007 that doesn’t even cite a number of people sampled in the abstract.

They didn’t run any experiments trying to change the diet or microbiome. They just correlated dietary preferences with some markers that might be correlated with the microbiome.

The paper does not say anything about how changing the microbiome might change preferences. The simplest and most well tested explanation is that dietary preference are driving the microbiome.

There’s a lot of woo-woo microbiome discussion out there that misses the really obvious basics of how the microbiome comes to exist and thrive: What you eat is what the microbiome eats, so changing what you eat will change the composition of bacteria that thrive. People who prefer chocolate are correlated with people who prefer sweet diets. High sugar intake is proven to alter the microbiome.

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mrtesthah 2 hours ago | parent | prev [-]

It makes sense for chocolate given that cocoa flavanols are prebiotic fiber for GABA-secreting bacteria which of course affects the parasympathetic nervous system.

	▲	Aurornis an hour ago \| parent [-]
		The paper didn’t say that the microbiome was driving food preferences. It measured some bio markers and some dietary preferences and claims some correlation. The correlation is that what you eat fuels the microbiome. So your diet influences the microbiome by fueling or starving different bacteria. Complex theories about causality going the other way through complex chains of flavonoids to bacteria to neurotransmitters to the parasympathetic nervous system sound impressive with all of the big words, but it’s such a complex theory that would need other testing to even begin to understand if there was something there. Testing the other direction is easy and obvious. You can grow many bacteria in a Petri dish and see that some grow better or worse with different nutrients.