“These results suggest that certain probiotics given to mothers during pregnancy can improve their offsprings’ behaviour and may affect the metabolism of common amino acids in our diets. Probiotics may also help counteract the negative effects of prenatal stress,” said study senior author Tamar Gur, MD, PhD, at OSU.
Many studies have attested to the benefits of probiotics, which are considered safe to take during pregnancy. Researchers led by first author Jeffrey Galley, PhD found that a specific probiotic, Bifidobacterium dentium, may change how the body processes certain amino acids, such as tryptophan. During pregnancy, tryptophan helps control inflammation and brain development.
“We have strong evidence this specific probiotic helped reduce stress-related problems in both mothers and their offspring, including helping the babies gain weight and improving their social behaviour,” said Gur, who also is an associate professor of psychiatry, neuroscience and obstetrics and gynaecology at Ohio State.
Gur’s research team has studied how prenatal stress can lead to abnormal brain development and behavioural changes in offspring. So far, they’ve found that stress is linked to changes in brain inflammation and amino acid metabolism, as well as long-term reductions in social behaviour and abnormal microbiomes in offspring.
This study enhances their understanding of how gut microbes and probiotics can influence amino acid metabolism and help with behaviour and immune issues related to prenatal stress. The study also highlights the many benefits of this specific probiotic, even without the presence of stress.
“Now, we aim to understand the mechanisms behind these changes and explore ways to prevent or treat these effects,” Gur said. “Since prenatal stress is common in many pregnancies, we want to develop methods to reduce its negative effects.”
Recent studies suggest that probiotics may offer a protective effect against hypertension, but how gut microbiota can regulate blood pressure has remained something of a mystery. Now a study published in mSystems showed that two probiotics, Bifidobacterium lactis and Lactobacillus rhamnosus, returned blood pressure in hypertensive mouse models to normal levels. The researchers also tracked how those probiotics altered the animals’ gut microbial mix over 16 weeks, identifying specific microbes and metabolic pathways that may help explain the protective effect.
“Accumulated evidence supports an antihypertensive effect of probiotics and probiotic fermented foods in both in vitro and in vivo experiments,” said computational biologist Jun Li, PhD, at the City University of Hong Kong. Her team worked with that of microbiologist Zhihong Sun, PhD, at Inner Mongolia Agricultural University, on the study. “So, we believed that the dietary intake of probiotic foods would well supplement traditional hypertension treatment.”
Previous studies have connected the rising rates of hypertension worldwide to increasing consumption of sugar. It likely boosts blood pressure through many mechanisms, such as increased insulin resistance or salt retention, but in recent years researchers have also investigated sugar’s effect on the gut microbiome.
In the new study, the researchers tested the two probiotic strains on mice that developed hypertension after consuming water mixed with fructose. Over the course of 16 weeks, they measured the animals’ blood pressures every 4 weeks. They found that fructose-fed mice that received either probiotic showed significantly lower blood pressures than those fed a high fructose diet and not treated with probiotics.
In addition, the researchers found no difference between the blood pressure readings of fructose-fed mice that received probiotics and a control group of mice that only drank water. According to Li, that suggests probiotic interventions would maintain blood pressure at normal levels.
The researchers used shotgun metagenomic sequencing to probe connections between the altered gut microbiota and the change in blood pressure. They found that a high-fructose diet in the mice led to an increase in Bacteroidetes and a decrease in Firmicutes bacteria; however, treatment with probiotics returned those populations to those found in the control group. In addition, the analysis identified new microbial signatures associated with blood pressure: Increased levels of Lawsonia and Pyrolobus bacteria, and reduced levels of Alistipes and Alloprevotella, were associated with lower blood pressure.
The researchers are now planning a large clinical trial to see if the protective effect of probiotics extend to people with hypertension. “Probiotics present a promising avenue in preventive medicine,” Sun said, “offering potential in regulating hypertension and reshaping our approach to cardiovascular health.”
Gut Microbiome. Credit Darryl Leja National Human Genome Research Institute National Institutes Of Health
Diarrhoeal disease outbreaks are on the increase in South Africa owing to unsafe or unhygienic water sources, which is being compounded by the effects of loadshedding.1 Equally, the deadly floods that affected particularly the Eastern Cape and KwaZulu-Natal in April last year damaged an already ailing sewerage and water system, with millions of litres of untreated sewage spilling onto beaches, rivers, harbours and the ocean in and around Durban.2
This has resulted in an increased incidence of gastroenteritis, which is caused by intestinal infection owing to the contamination of food, water or hands.3 Acute-onset vomiting and diarrhoea is second only to respiratory illnesses as a cause of childhood deaths worldwide.3
Diarrhoea accounts for 19% of deaths of under-fives in South Africa and for 46% on the African continent.4 Acute diarrhoea has several risks and complications, and may lead to life-threatening dehydration and electrolyte disturbances.3 When diarrhoea is not halted, there is a risk of disturbed digestion and absorption of nutrients with nutritional deterioration.3
Guidelines published in the South African Medical Journal (SAMJ) state that acute diarrhoea is predominantly a problem of fluids and feeding – both being heavily dependent on the caregiver’s understanding and reactions.3
It is vital that healthcare practitioners and caregivers understand the ‘what’ and the ‘how’ of oral rehydration therapy (ORT) and re-feeding, and that they are given guidance on the need to seek further help in the event of the following:3
• Ongoing vomiting despite small fluid sips, especially if associated with abdominal distension or pain
• Persisting fever after 24 hours of ORT
• Increasing lethargy and failure to feed
• Deteriorating hydration and failure to pass urine
• Presence of blood in the stools
• Diarrhoea persisting for more than 1 week.
Momeena Omarjee, Consumer Healthcare Country Head: Scientific Affairs, at Sanofi South Africa, outlines an ambitious campaign by Sanofi in partnership with non-profit organisation (NPO), Save the Children, to impact over 2 000 000 lives by 2025, through education on hygiene and nutrition and improved access to water.
“Sanofi is committed to ensuring that no child dies of a preventable disease. Since October 2022, Sanofi has donated 15 water tanks and 14 hand-washing stations to Early Childhood Development centres in KwaZulu-Natal communities in need, to ensure access to clean, drinkable water. This will help to curb the prevalence of diarrhoea and diarrhoea-associated deaths in children under five, which are entirely avoidable,” says Omarjee.
“Children living in poverty-stricken environments are approximately 10 times more likely to die from diarrhoea than their more privileged counterparts.5 Providing adequate access to clean, drinkable water and quality early childcare and development will impact the lives and health of so many vulnerable children,” says Omarjee.
Several studies have shown that probiotics shorten the duration of diarrhoea and prevent recurrence of other episodes.6 Furthermore, probiotics can prevent diarrhoea from infection in infants with malnutrition.6
The World Gastroenterology Organisation states that oral administration of probiotics shortens the duration of acute diarrheal illness in children by approximately 1 day.7 There is also evidence of efficacy in adults or children who are receiving antibiotic therapy, for prevention of antibiotic-associated diarrhoea.7
“Healthcare professionals should encourage parents to give children a daily, regular probiotic, which could go a long way in preventing diarrhoea and illness,” concludes Omarjee.
Wittenberg, DF. 2012. Management guidelines for acute infective diarrhoea/gastroenteritis in infants. SAMJ, vol. 102, No. 2.
Awotione, O.F., et al. 2016. Systematic review: Diarrhoea in children under five years of age in South Africa (1997-2014). Tropical Medicine and International Health, 21(9), 1060-1070.
Chola, L., et al. 2015. Reducing diarrhoea deaths in South Africa: costs and effects of scaling up essential interventions to prevent and treat diarrhoea in under five children. BMC Public Health, 15, 394.
Solis, B. et al. 2002. Probiotics as a help in children suffering from malnutrition and diarrhoea. European Journal of Clinical Nutrition, 56, S57-59.
Researchers at the University of Helsinki have created a strain of the Lacticaseibacillus rhamnosus GG probiotic that can reproduce in dairy products.
Lacticaseibacillus rhamnosus GG, or LGG, is the most studied probiotic bacterium in the world. However, it cannot utilise lactose found in milk or break down the milk protein casein. This makes the bacterium grow poorly in milk and is the reason why it must be added separately to probiotic dairy products.
While attempts have been made to get L. rhamnosus GG to thrive in milk through genetic engineering, strict restrictions have prevented the use of such modified bacteria in human food.
Thanks to a recent breakthrough made at the University of Helsinki, Finland, with researchers from the National Institute for Biotechnology and Genetic Engineering, Pakistan, features have now been successfully added to the LGG probiotic without gene editing, making it able to grow in milk.
The method instead took advantage of conjugation, a DNA exchange technique used in certain bacterial groups to transfer their traits to other bacteria. A bacterium produces a copy of its plasmid, a ring-shaped piece of DNA, and then transfers it to an adjacent bacterium. The spread of plasmids, which carry traits useful for bacteria, can be rapid among bacterial communities – and can also further the spread of problematic traits such as antibiotic resistance.
A specific Lactococcus lactis bacterial strain grown in the same place provided the lactose and casein-utilising plasmid to the Lacticaseibacillus rhamnosus GG.
“The new LGG strain is not genetically modified, which makes it possible to consume it and any products containing it without any permit procedures,” explained project leader Per Sari, Professor of Microbiology at the University of Helsinki.
The new strain can be used as a starting point in the development of new dairy products where the probiotic concentration increases already in the production stage. In other words, the probiotic need not be separately added to the final product. Furthermore, lactose- and casein-hydrolysing bacteria added to milk could help produce products suitable for people with dairy allergies.
This new LGG strain could also be better suited to growing in the infant gut, where it can utilise the casein and lactose in breastmilk to grow, thereby producing more protective lactic acid than the original strain.
“Lactic acid lowers the pH of the surface of the intestine, reducing the viability of many gram-negative pathogenic bacteria, such as E. coli, Salmonella and Shigella, which threaten the health of infants. Moreover, in larger numbers the new LGG strain can potentially be more effective at protecting infants than the old strain. After all, LGG has previously been shown to alleviate infantile atopic dermatitis and boost the recovery of the gut microbiota after antibiotic therapies.”
The researchers are in discussions about further applications of their research.
Journal information: Hussain, N., et al. (2021) Generation of Lactose- and Protease-Positive Probiotic Lacticaseibacillus rhamnosus GG by Conjugation with Lactococcus lactis NCDO 712. Applied and Environmental Microbiology. doi.org/10.1128/AEM.02957-20.
