Broccoli improves your gut bacteria

Posted on Mon, 3 Jul 17

Recent studies have revealed what happens to your gut bacteria when you eat broccoli, and the effects are remarkable. 

While there has been a tremendous amount of study on the effects of probiotics and prebiotic supplements on our gut bacteria, relatively few studies have investigated the effects of whole foods. Any influence of whole foods on our gut bacteria would be important to understand because our gut bacteria can influence our overall health. 

Broccoli and other cruciferous vegetables have been associated with important health benefits, especially cancer prevention, which is thought to be due to their exceptional nutritional profile, including high amounts of fiber, vitamin c, folate, and phytonutrients called glucosinolates which are unique to cruciferous vegetables.

But two new studies suggest that the benefits of cruciferous vegetables may be just as much due to their effects on our gut bacteria. 

In the first study, eating 200 g of cooked broccoli and 20 g of fresh daikon radish daily for 17-days improved overall bacterial diversity and the Bacteroidetes to Firmicutes ratio, which increased by 37% compared to a 5% reduction during a Brassica-free control diet [1]. 

And in the second study, eating six 84 g portions of broccoli, six 84 g portions of cauliflower and six 300 g portions of a broccoli and sweet potato soup over 2-weeks reduced reduced relative abundance of hydrogen sulphate producing bacteria [2]. 

What does this all mean? Well, greater bacterial diversity has been linked to better metabolic health, including lower body fat, better blood sugar regulation, better blood cholesterol and reduced inflammation [3].  And lower levels of hydrogen sulphate producing bacteria is associated with better gastrointestinal health and lower risk of disorders such as irritable bowel syndrome [4].

So, eating cruciferous vegetables regularly is good for you, and your microbiome. 

References: 

1. Kaczmarek JL, et al. Broccoli Consumption Impacts the Human Gastrointestinal Microbiota. April 2017. The FASEB Journal. vol. 31 no. 1 Supplement 965.18
2. Kellingray L, et al. Consumption of a diet rich in Brassica vegetables is associated with a reduced abundance of sulphate-reducing bacteria: A randomised crossover study. Mol Nutr Food Res. 2017 Mar 10. doi: 10.1002/mnfr.201600992. [Epub ahead of print]
3. Le Chatelier E, et al. Richness of human gut microbiome correlates with metabolic markers. Nature. 2013  Aug 29;500(7464):541-6.
4. Chassard C, et al., Functional dysbiosis within the gut microbiota of patients with constipated-irritable bowel syndrome. Aliment. Pharmacol. Ther. 2012, 35, 828–838.