Early Life Gut Microbiota and Vitamin D Supplements

Research Reviews

Every week we review and summarize two articles, research papers or scientific reviews. This week, we chose one review from Diabetologia and a research article from the Journal of Nutrition.

Review: Early Life Gut Microbiota is Affected by Maternal Weight Status.

Article: Microbial transmission from mothers with obesity or diabetes to infants: an innovative opportunity to interrupt a vicious cycle.

Summary: This scientific review discussed the development of the gut microbiota in early life, the factors affecting it and how it may affect health later in life.

Review: Vitamin D Supplements May Help Fight Depression.

Article: Vitamin D Supplementation Affects the Beck Depression Inventory, Insulin Resistance, and Biomarkers of Oxidative Stress in Patients with Major Depressive Disorder: A Randomized, Controlled Clinical Trial.

Summary: This randomized controlled trial examined the effects of vitamin D supplements on symptoms of depression. It suggested that supplements may improve depression symptoms for those who are vitamin D-deficient.

New Research From Around the World

Lots of new papers were published this week. Here are summaries of the most interesting or relevant studies, categorized by subject.

1. Obesity and Weight Loss

Effects of dietary pulse consumption on body weight: a systematic review and meta-analysis of randomized controlled trials.

The seeds of legumes — beans, peas and lentils — are collectively known as pulses. High consumption of pulses has been linked with a variety of health benefits, but their effects on weight loss are unclear.

This systematic review and meta-analysis of randomized controlled trials showed that eating pulses may be an effective weight loss strategy, even on a diet that is not calorie-restricted.

Maternal caffeine intake during pregnancy, early growth, and body fat distribution at school age.

This observational study in pregnant women found that high caffeine intake, equivalent to 6 or more cups of coffee per day, was associated with lower birth weight, compared to caffeine intake equivalent to less than 2 cups per day.

What’s more, the children of mothers who consumed lots of caffeine had a higher body mass index from 6 months of age up to 6 years. They also gained more weight.

DHA supplementation during pregnancy does not reduce BMI or body fat mass in children: follow-up of the DHA to Optimize Mother Infant Outcome randomized controlled trial.

Docosahexaenoic acid (DHA) is an omega-3 fatty acid abundant in fatty fish, fish oil and certain types of marine algae.

This randomized controlled trial found that intake of DHA-rich fish during the second half of pregnancy does not have any effects on body mass index or fat gain in children when they are 3–5 years old.

Association of breakfast consumption with body mass index and prevalence of overweight/obesity in a nationally-representative survey of Canadian adults.

This observational study in Canadian adults indicates that skipping breakfast is not associated with a higher body mass index.

Unhealthy eating behaviors and weight gain: A prospective study in young and middle-age adults.

This prospective observational study examined the association of several unhealthy eating behaviors with weight gain.

The three eating behaviors that were linked with the most weight gain were: 1) not planning the amount of food to eat, 2) eating at fast-food restaurants and 3) and eating while watching TV.

2. Blood Sugar Control and Diabetes

Serum n-6 polyunsaturated fatty acids, Δ5- and Δ6-desaturase activities, and risk of incident type 2 diabetes in men: the Kuopio Ischaemic Heart Disease Risk Factor Study.

This observational study found that higher circulating levels of omega-6 fats, linoleic acid and arachidonic acid were linked with a lower risk of type 2 diabetes.

Conversely, higher levels of dihomo-gamma-linolenic acid were associated with a higher risk of type 2 diabetes.

Diet low in advanced glycation end products increases insulin sensitivity in healthy overweight individuals: a double-blind, randomized, crossover trial.

Advanced glycation end products (AGEs) are a group of compounds that naturally form in our bodies when sugar reacts with protein. High blood sugar levels promote their formation, but AGEs are also found in some processed food products.

This randomized controlled trial showed that a diet low in AGEs increases insulin sensitivity, potentially reducing the risk of type 2 diabetes.

Coffee consumption, obesity and type 2 diabetes: a mini-review.

This small scientific review concluded that regularly drinking 3–4 cups of coffee per day may reduce the risk of type 2 diabetes. These effects are likely due to two active components of coffee: chlorogenic acid and caffeine.

3. Heart Health

Urinary potassium excretion and risk of cardiovascular events.

Previous observational studies indicate that dietary intake of potassium is weakly or modestly associated with a reduced risk of heart disease.

This long-term, prospective observational study examined the amount of potassium in urine, which is a good marker of dietary potassium intake. However, potassium in urine was not independently linked to a reduced risk of heart disease events.

Dietary Approaches to Stop Hypertension Diet and Incidence of Stroke: Results From 2 Prospective Cohorts.

DASH stands for Dietary Approaches to Stop Hypertension. It is a popular diet, designed to reduce blood pressure. This observational study suggests that adhering to the DASH diet may reduce the risk of stroke.

Effect of whey protein on blood lipid profiles: a meta-analysis of randomized controlled trials.

This meta-analysis of randomized controlled trials examined how whey protein affects the blood lipid profile. It lowers triglycerides, but has no effects on total cholesterol, LDL-cholesterol or HDL-cholesterol.

4. Cancer

Calcium and 1,25-dihydroxy vitamin D3 modulate genes of immune and inflammatory pathways in the human colon: a human crossover trial.

Previous studies suggest that a high intake of calcium and adequate vitamin D may reduce the risk of colorectal cancer. This crossover trial examined the effects of supplementing with vitamin D and calcium while following a typical Western Diet.

The study showed that supplementing with 1,25-dihydroxyvitamin D3 (vitD) increased the activity of genes involved with inflammation and immune responses in the colon. However, taking calcium with vitD reversed these effects.

Prospective study of dietary phytoestrogen intake and the risk of colorectal cancer.

Phytoestrogens are plant compounds that resemble the female sex hormone, estrogen, and may have an estrogen-like activity in the body. Some observational studies have linked them with an increased risk of prostate and breast cancer.

This observational study suggests that a high intake of phytoestrogens has no effects on the risk of colorectal cancer.

Association between folate status and cervical intraepithelial neoplasia.

Intraepithelial neoplasia (IN) is an abnormal growth on the surface of the cervix in the lower part of the uterus. It’s not cancer, but may develop into cancer if left untreated.

This observational study in Chinese women found that low levels of circulating folate were linked with an increased risk of IN progression.

Plasma equol concentration is not associated with breast cancer and fibrocystic breast conditions among women in Shanghai, China.

Daidzein is an isoflavone found in soybeans. In some people, intestinal bacteria convert daidzein into equol. High circulating levels of equol have been associated with a number of health benefits.

This observational study in Chinese women suggests that equol has no effects on the risk of breast cancer.

5. Appetite and Eating

Factors influencing adolescent whole grain intake: A theory-based qualitative study.

One fifth of people in the UK do not eat any whole grains.

This qualitative study found that the main barriers to eating whole grains were difficulties identifying whole-grain food products, bland taste, lack of knowledge on their health benefits and poor availability outside the home.

Factors influencing fruit and vegetable intake among urban Fijians: A qualitative study.

This qualitative study found that the main barriers to eating vegetables and fruits among urban Fijians were increased preferences for processed food and inconsistent availability of high-quality, low-priced, fresh produce.

The importance of taste on dietary choice, behaviour and intake in a group of young adults.

1,306 Australian university students answered a questionnaire assessing their dietary behavior. When it came to food choice, 84% of them rated taste as a very or extremely important factor.

Those who rated taste as highly important had a lower dietary quality, compared to those who considered taste to be less important. For example, they ate much less whole food, but greater amounts of processed junk food.

6. Brain and Mental Health

Association of seasonal serum 25-hydroxyvitamin D levels with disability and relapses in relapsing-remitting multiple sclerosis.

Multiple sclerosis (MS) is a disease characterized by speech difficulties, tremors, loss of coordination, impaired memory and other symptoms.

This observational study in MS patients found that vitamin D status was worse in the winter than in the summer. It also suggests that a poor vitamin D status is linked with a more severe MS and more frequent relapses.

7. Digestive Health

Inflammatory potential of diet and risk of ulcerative colitis in a case–control study from Iran.

Ulcerative colitis is a type of inflammatory bowel disease characterized by inflammation and small sores (ulcers) in the lining of the colon. The main symptom of an active disease is blood-mixed diarrhea.

This observational study in Iranian adults found that a pro-inflammatory diet, according to the dietary inflammatory index, was associated with an increased risk of ulcerative colitis.

8. Bone Health

Food fortification for bone health in adulthood: a scoping review.

This review concluded that supplementing with calcium and/or vitamin D benefits bone metabolism, reducing the risk of osteoporosis and fractures.

9. Muscles and Physical Performance

Vitamin D3 supplementation using an oral spray solution resolves deficiency but has no effect on VO2 max in Gaelic footballers: results from a randomised, double-blind, placebo-controlled trial.

This randomized controlled trial showed that for Gaelic footballers, taking 3,000 IU of vitamin D3 every day for 3 months did not have any effects on aerobic fitness (as measured by VO2 max), muscle or lung function.

10. Sleep

Moderately high-dose of the artificial sweetener saccharin potentially induces sleep disorders in mice.

This mouse study suggests that eating saccharin, 0.1% weight/volume for two weeks, disrupts the sleep-wake cycle. Specifically, it reduced wakefulness during the day and impaired sleep quality.