Health benefits of raisins may improve the microbiome

Are there health benefits of raisins? Well, if you look at their nutrition info, there’s not much to get excited about. Aside from a decent dose of potassium(300mg), not much else sticks out. Maybe the high sugar content, which isn’t exactly a ringing endorsement.

However, if you dig in a little deeper, there do seem to be some beneficial aspects of raisins. They have a bit of fiber, and they have some polyphenols.

As a result of their polyphenol content, raisins have a high antioxidant capacity. They have an oxygen radical absorbance capacity(ORAC) score of 2830. For commonly consumed fruit, this is second only to prunes.

But what about the gut? Are there health benefits of raisins that target the gut? Based on some recent evidence, it appears there are.

Health benefits of raisins

Gut health benefits of raisins

A recent paper took a look at how raisins impact the microbiome in healthy adults. While they didn’t find huge swings in diversity, they did find some beneficial changes.

People consuming 28g of raisins 3x/day saw increases in beneficial members from Bacteroidetes sp. and Ruminococcus sp. They also saw decreases in opportunistic bad guys from Prevotella sp. and Klebsiella sp. Though there were also decreases in some Bifidbacterium sp. and increases in other, the method they used to measure isn’t good at picking them up.

However, the most striking improvement in the study was that there was an across the board increase in Faecalbacterium prausnitzii. F. prausnitzii is an important member of the human microbiome that acts as a keystone species.

Keystone species are crucial for the gut microbiome because they attract other beneficial microbes through various interactions. Furthermore, as discussed in a previous blog, F. prausnitzii is a microbe depleted in chronic fatigue syndrome and long covid.

The improvements in good guys was attributed to the polyphenol and fiber content. In particular, they have a good dose of inulin, which may promote F. prausnitzii. This may be why they increase short chain fatty acids.

The decrease in bad guys was attributed to a potential decrease in inflammation from the SCFAs and a possible antimicrobial effect of the poyphenols.


There may be some significant health benefits from raisins due to improvements in the microbiome. Previous evidence shows that raisins improve stool weight, speed up transit, decreased fecal bile acids, and increase SCFAs.

Based on the evidence, consuming raisins daily may have beneficial effects on gut health and the microbiome. The sweet spot based on the evidence seems to be a quarter cup twice a day.

Personally, I do a quarter cup medley of Thompson’s seedless raisins and golden raisins once a day. I add the golden raisins because, although the nutrition info is the same, the polyphenol content is not. As a result, golden raisins have a higher ORAC value.

If you’re concerned about the sugar content, it actually appears that raisins improve glycemic control at the dose recommended in these studies. This is likely due to their polyphenol content. Note: Carbs/sugar=bad for blood glucose is such a bad take based on poor knowledge on blood glucose regulation. Definitely guilty of this in the past.

Raisins blood glucose
Serum glucose after 69g raisins or 50g of glucose

Give raisins a try and see how they impact your digestion. Let us now what you think in the comments section below.

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