How can you improve your microbiome?
Top practices and therapies for managing your microbiome
Therapies we have reviewed
Conventional treatments include fecal microbiome transplant, which transfers fecal material rich in microbes from a host with a healthy microbiome to a person with a poorer microbiome. A separate host/donor is used for fecal material (stool) when a person has an infection, such as C. difficile, that is difficult to treat and which can respond well to the introduction of desired microbes. A donor‘s stool sample may also be used to populate the gut with desired microbes for other reasons.
Another variation involves a person with a healthy microbiome providing a stool sample before undergoing antibiotic treatment. This is called an autologous—”from oneself”—transplant. After antibiotic treatment ends, the person’s own stool and microbes are re-introduced.
Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) shows this to be an effective way to repopulate a healthy gut microbiome—more effective than using probiotics.
- Rapid return to baseline stool microbiome configuration after 7 days of antibiotic treatment among healthy volunteers treated with autologous fecal microbiome transplant, substantially more rapid than watchful waiting for spontaneous microbiome reconstitution or treatment with an 11-strain probiotics preparation twice a day for 4 weeks in a small controlled triala study design in which people are assigned to either an experimental group or a control group to compare the outcomes from different treatment; assignment is not random, and so this is not as strong a study design as a randomized controlled trial, but still stronger than an uncontrolled trial1Suez J, Zmora N et al. Post-antibiotic gut mucosal microbiome reconstitution is impaired by probiotics and improved by autologous FMT. Cell. 2018 Sep 6;174(6):1406-1423.e16.
Evidence supporting the statements here is described on the linked pages.
Eating Well: good and modest evidence
- Diet is a major factor driving the composition and metabolism of the microbiota of the colon (good evidencesignificant effects in one large or several mid-sized and well-designed clinical studies (randomized controlled trials (RCTs) with an appropriate placebo or other strong comparison control or observational studies that control for confounds) (this is the CancerChoices definition; other researchers and studies may define this differently)).
- Changing your diet can bring rapid and significant changes to your microbiome (modest evidence).
- A healthier microbiome is found among people following the recommended dietary patterns of plant-based foods and minimal red and processed meats (modest evidencesignificant effects in at least three small but well-designed randomized controlled trials (RCTs), or one or more well-designed, mid-sized clinical studies of reasonably good quality (RCTs or observational studies), or several small studies aggregated into a meta-analysis (this is the CancerChoices definition; other researchers and studies may define this differently)). Foods that promote a healthy microbiome include cruciferous vegetables (broccoli family), whole grains, fermented foods, and foods high in fiber.
- More frailty and less community-associated microbiota diversity among elderly people in long-term residential care eating diets with more fat and less fiber (preliminary evidence)
Moving More: modest evidence
Healthier microbiota among healthy people with higher levels of physical activity (modest evidence)
Sleeping Well: preliminary evidence
Alterations in the fecal microbiome of people with sleep disturbance (preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently))
Manage your body weight: modest evidence
As you gain weight beyond a normal body weight, the ratio of some microbes changes, which can be reversed by losing weight.
Worse microbial balance among people who are obese and improved balance among people losing weight (modest evidence)
Alcohol, smoking, and drug use
Limiting alcohol and refraining from smoking and recreational drug use are good approaches to keeping your microbiome healthy.
We’re working to review all the evidence related to these lifestyle behaviors. These findings are from our research to date.
Evidence supporting the statements here is described on the linked pages.
Strong or good evidence of benefit
Strong evidenceconsistent, significant effects in several large (or at least one very large) well designed clinical studies or at least two meta-analyses of clinical studies of moderate or better quality (or one large meta-analysis) finding similar results (this is the CancerChoices definition; other researchers and studies may define this differently) indicates a high degree of confidence that the therapy is linked to the outcomes as noted. Good evidencesignificant effects in one large or several mid-sized and well-designed clinical studies (randomized controlled trials (RCTs) with an appropriate placebo or other strong comparison control or observational studies that control for confounds) (this is the CancerChoices definition; other researchers and studies may define this differently) indicates a relatively high degree of confidence that the therapy is linked to the outcomes as noted.
Mediterranean diet: strong evidence
An alteration of gut microbiota to a status associated with less inflammation, reduced risks of disease, and eubiosis in general among people following a Mediterranean diet (strong evidence)
Probiotics: mixed evidence
Better microbiome status among people treated with probiotics, including during chemotherapy and surgery (good evidence)
Less disruption or beneficial changes to the gut/fecal microbiome of people treated with probiotics (preliminary evidence)
Higher abundance of microbial genera after surgery among people treated with probiotics (preliminary evidence)
Less bacterial vaginosis among people treated with oral probiotics (preliminary evidence)
No evidence of an effect on oral bacterial community composition or diversity after radiotherapy among people with head and neck cancer treated with oral probiotics in a small trial
Not specific to cancer:
- Beneficial changes in the microbiomes of people treated with prebiotics (preliminary evidence)
We’re finalizing our review of Probiotics and Prebiotics; the evidence for these assessments will be available soon.
Preliminary evidence of benefit
Preliminary evidencesignificant effects in small or poorly designed clinical studies OR conflicting results in adequate studies but a preponderance of evidence of an effect (this is the CancerChoices definition; other researchers and studies may define this differently) typically indicates that not much research has been published so far, although the outcomes may be meaningful.
Better intestinal bacteria after colorectal resection surgery among people treated with warm needle acupuncture and moxibustion (preliminary evidence)
Health-promoting changes in skin and gut microbiota among urban daycare children with greater exposure to nature (preliminary evidence)
Your microbiome and gut surgery
Colorectal and other gastrointestinal surgeries are invasive and disrupt the microbial balance in the gut. This disruption can lead to reduced function of your gut barrier, which normally allows the absorption of nutrients into your blood while keeping bacteria and other pathogens from spreading through your body. Disruption can also lead to a local immune response, systemic inflammation, and potentially even infection after surgery.2Anderson SW, Bazzell AF, Dains JE. An integrative review on the effect of prebiotics, probiotics, and synbiotics on infection after colorectal cancer surgery. AORN Journal. 2018;107(2):237–248. Prebiotics and probiotics may be helpful as described next.
Commentary: microbiome and surgery
CancerChoices Senior Clinical Consultant Laura Pole, RN, MSN, OCNS: Integrative physician and CancerChoices advisor Keith Block, MD, and other clinician researchers suggest using prebiotics or probiotics before and after surgery to reduce the risk of infection and keep the protective inner lining of the intestines (mucosal barrier) healthy.3Block KI, Block PB, Gyllenhaal C. Integrative treatment for colorectal cancer: a comprehensive approach. The Journal of Alternative and Complementary Medicine. 2018 Sep/Oct;24(9-10):890-901. This is backed by research: Use of probiotics around the time of surgery improved the gut microbiome4Aisu N, Tanimura S et al. Impact of perioperative probiotic treatment for surgical site infections in patients with colorectal cancer. Experimental and Therapeutic Medicine. 2015;10(3):966–972. and protected the intestinal lining’s physical and biological barrier5Liu D, Jiang XY, Zhou LS, Song JH, Zhang X. Effects of probiotics on intestinal mucosa barrier in patients with colorectal cancer after operation: meta-analysis of randomized controlled trials. Medicine (Baltimore). 2016 Apr;95(15):e3342. after colorectal cancer surgery.
I encourage you to consult your surgeon and/or an integrative oncologist—such as a naturopathic oncologist or functional medicine physician—to recommend specific probiotics you can take as well as other measures to protect and restore your microbiome.
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