---
title: "Research Review: Broccoli for Supporting Gut Microbial Health"
description: In a crossover study of 18 adults, broccoli and daikon radish reduced Firmicutes by 9% and raised Bacteroidetes by 10%, most in higher-BMI participants.
---

[Evidence-based Wellness Education](https://www.casi.org/articles)

# [Research Review: Broccoli for Supporting Gut Microbial Health](https://www.casi.org/articles/broccoli-for-supporting-gut-microbial-health)

 Written by [Danielle C. Male, MS, CNS, LDN](https://www.casi.org/articles/author/danielle-c-male-ms-cns-ldn) | Dec 8, 2022, 5:00:00 AM

Research suggests that a healthy gut microbial environment influences overall health. The amount, diversity, and type of beneficial microorganisms in the gut microbiome may [promote gastrointestinal health, immune health, energy metabolism, digestion, and vitamin synthesis](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9286904/). Broccoli, a cruciferous vegetable, contains [dietary fibers and phytonutrients](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025206/) that may enhance the production and proliferation of beneficial bacteria. Broccoli contains [glucosinolate](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025206/) phytonutrients that the microbiome can metabolize into bioactive [isothiocyanates](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025206/). The isothiocyanates have been shown to support a [healthy immune system](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025206/) and attenuate the adverse effects of [diverse pathologies](https://pubmed.ncbi.nlm.nih.gov/29573889/).  

[Kaczmarek and colleagues](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025206/) conducted a controlled feeding, randomized, crossover study in healthy adults (n = 18) with two 18-day treatment periods separated by a 24-day washout period. In the intervention period, the adults were fed 200 g of cooked broccoli and 20 g of raw daikon radish per day. Compared to the relative controls, the individuals in the [broccoli group](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025206/) displayed increased function of the endocrine system, transport and catabolism, and energy metabolism. Moreover, the [broccoli group](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025206/) exhibited a decreased relative abundance of *Firmicutes* by 9% and an increased relative abundance of *Bacteroidetes* by 10% and *Bacteroides* by 8%. The effects were [most potent](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025206/) in participants with a body mass index greater than 26 kg/m2. A higher value of the *Bacteroidetes* to *Firmicutes* ratio that resulted in this experiment has been shown to [promote healthy body weight in certain studies](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8025206/). 

The antimicrobial properties of broccoli have been reported in various publications. An [in vitro disease model](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7465980/) determined that broccoli sprouts have antibacterial activity against Gram-positive bacteria (*Staphylococcus aureus* and *Bacillus subtilis*) and Gram-negative bacteria (*Salmonella typhimurium* and *Escherichia coli*). [Gram-positive bacteria were more sensitive to broccoli sprout extract than gram-negative bacteria](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7465980/). [In vitro, animal, and human clinical studies](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7465980/) using broccoli sprout administration demonstrate the attenuation of *H. Pylori* infection due to the high sulforaphane content of broccoli sprouts. One [clinical study](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5600105/) showed that a high-*Brassica* diet (including broccoli) might reduce the relative abundance of sulfur-reducing bacteria associated with [ulcerative colitis and irritable bowel syndrome](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5600105/). 

In a [randomized, double-blind, controlled trial](https://pubmed.ncbi.nlm.nih.gov/35831736/), patients with *H. pylori* infection without atrophic gastritis (n = 110) were administered a placebo or broccoli seed extract supplementation for 2 months. Compared to the placebo, the individuals receiving the [broccoli seed extract supplementation](https://pubmed.ncbi.nlm.nih.gov/35831736/) displayed a higher rate of *H. Pylori* eradication, reduced risk of gastric mucosal lesions, and reduced inflammatory cytokines, including interleukin-8, interferon-gamma, pepsinogen (PG) I, PG I/PG II ratio, and gastrin-17.

The glucosinolate polyphenols in broccoli may be clinically relevant in supporting overall gastrointestinal health. Research indicates that dietary broccoli, broccoli sprouts, or broccoli seed extract supplementation may promote a healthy gut microbial environment. 

[View full post](https://www.casi.org/articles/broccoli-for-supporting-gut-microbial-health)

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