Medical Bulletin 27/January/2024

Here are the top medical news of the day:

A new study reveals new protective benefit of breast milk

An immune component of breast milk known as the complement system shapes the gut environment of infant mice in ways that make them less susceptible to certain disease-causing bacteria, according to a study led by researchers at the Johns Hopkins Bloomberg School of Public Health.

The researchers found that mouse pups that nursed from lactating mice whose breast milk lacked a key complement protein had different gut microbe populations than pups that nursed on standard mouse breast milk, making them highly vulnerable to Citrobacter rodentium, a bacterium that infects the guts of mice. Citrobacter rodentium is similar to certain types of diarrhea-causing E. coli that can infect humans but not mice.

The study was published online in the journal Cell.

The researchers’ experiments suggest that mouse breast milk’s complement components boost mouse infant health by directly eliminating some types of gut-dwelling bacteria. This reshaping of the gut microbiota leaves the infant mice far less susceptible to Citrobacter rodentium infection, thus protecting the young from certain infectious threats. The reshaping activity is not dependent on antibodies, in contrast to the way complement components are thought to typically work.

The researchers also confirmed in separate in vitro analyses that human breast milk contains these complement components, which demonstrated similar activity in targeting specific bacteria.

Taken together, these findings shed light on the mechanisms of how breast milk functions to provide protection from certain bacterial infections.

”These findings reveal a critical role for breast milk complement proteins in shaping offspring’s gut microbe compositions and protecting against bacterial infection in the gut in early life,” says study senior author Fengyi Wan, PhD, a professor in the Bloomberg School’s Department of Biochemistry and Molecular Biology. “This represents an important expansion of our understanding of breast milk’s protective mechanisms.”

Reference: Study in mice uncovers new protective benefit of breast milk; Cell; DOI: 10.1016/j.cell.2023.12.019

Cold water swimming improves menopause symptoms

Menopausal women who regularly swim in cold water report significant improvements to their physical and mental symptoms, finds a new study led by UCL researchers.

The research, published in Post Reproductive Health, surveyed 1114 women, 785 of which were going through the menopause, to examine the effects of cold water swimming on their health and wellbeing.

The findings showed that menopausal women experienced a significant improvement in anxiety (as reported by 46.9% of the women), mood swings (34.5%), low mood (31.1%) and hot flushes (30.3%) as a result of cold water swimming.

In addition, a majority of women (63.3%) swam specifically to relieve their symptoms.

Some of the women quoted in the study said that they found the cold water to be “an immediate stress/ anxiety reliever” and described the activity as “healing”.

One 57-year-old woman stated: “Cold water is phenomenal. It has saved my life. In the water, I can do anything. All symptoms (physical and mental) disappear and I feel like me at my best.”

Senior author, Professor Joyce Harper (UCL EGA Institute for Women’s Health), said: “Cold water has previously been found to improve mood and reduce stress in outdoor swimmers, and ice baths have long been used to aid athletes’ muscle repair and recovery.

“Our study supports these claims, meanwhile the anecdotal evidence also highlights how the activity can be used by women to alleviate physical symptoms, such as hot flushes, aches and pains.

“More research still needs to be done into the frequency, duration, temperature and exposure needed to elicit a reduction in symptoms. However, we hope our findings may provide an alternative solution for women struggling with the menopause and encourage more women to take part in sports.”

Reference: Cold water swimming improves menopause symptoms; Post Reproductive Health; DOI: 10.1177/20533691241227100

Mood interventions might help reduce inflammation in Crohn’s and Colitis

New King’s College London research reveals that interventions which improve mood can reduce levels of inflammation in people with inflammatory bowel disease by 18 per cent, compared to having no mood intervention.

Researchers at the Institute of Psychiatry, Psychology & Neuroscience at King’s College London found that interventions designed to improve mood, including psychological therapy, antidepressants, and exercise, were associated with significant reductions in inflammatory biomarker levels in individuals with inflammatory bowel disease (IBD). Interventions for mood may present an alternative treatment for IBD that is both effective and low-cost.

Inflammatory biomarkers can be found in the body to indicate areas and types of inflammation. Researchers analysed existing studies on levels of the biomarkers C-Reactive Protein and faecal calprotectin which are specific indicators of IBD, as well as a combined measure of other inflammatory biomarkers.

The systematic review and meta-analysis published in eBiomedicine, part of The Lancet Discovery Science, is the first to investigate the relationship between interventions aiming to treat mood and levels of inflammatory biomarkers in IBD. The findings suggest that interventions for mood present a strategy to improve mental health and reduce inflammation in IBD.

The researchers conducted a search of more than 15,000 articles, looking for all randomised controlled trials in adults with IBD that measured levels of inflammatory biomarkers and tested a mood intervention (for example, interventions to reduce depression, anxiety, stress and distress, or improve emotional wellbeing).

They reviewed and analysed data from 28 randomised controlled trials involving over 1,700 participants to establish whether interventions targeting mood outcomes impact inflammation levels in IBD.

Researchers found that psychological therapies, including Cognitive Behavioural Therapy (CBT), Acceptance and Commitment Therapy, and Mindfulness Based Stress Reduction, had the best outcomes on inflammation in IBD, compared with antidepressants and exercise interventions. Interventions which had a larger positive effect on mood had a greater effect on reducing inflammatory biomarkers. These findings suggest that the mechanism underlying the effect of psychological and social interventions on inflammation in IBD could be improved mood.

Reference: Mood interventions may reduce inflammation in Crohn’s and Colitis; EBioMedicine; DOI: 10.1016/j.ebiom.2023.104910