We’ve all heard that probiotics are good for our gut, but now there are claims they can help your skin? Dr Hannah Sweilem looks at the evidence.

Trends in skincare come and go as we know, but one that’s growing in popularity now is idea that probiotics – the good bacteria that live in our guts – can help improve our skin. But the idea is not new.

Back in the day (in 1930 to be precise), two well-known dermatologists made a prediction: that gut health affects skin health. They predicted that an imbalance of gut microbes increases gut permeability (‘leakiness’), causing toxins to leak out of the gut, which increases inflammation throughout the body and affects skin. They were among the first to advocate the use of probiotics to treat the skin.

The idea of the gut and skin being closely linked is not as far-fetched as it might seem. Chemical messengers in the body send signals between organs, including between the gut and skin, and these two organs are linked in the sense that they have a common embryonic origin (that is, they originate from the same layer of cells in the developing embryo).  Many gut conditions, such as Crohn’s disease and ulcerative colitis, have skin manifestations including rashes and blistering.

Evidence of a gut-skin link

Just as predicted back in 1930, a modern-day study has confirmed an association between imbalance of gut bacteria and increased gut permeability.

Another study, which looked at patients with acne, found in some of those patients’ bloodstream a toxin produced by the gut microbe, E. Coli.  This suggests that increased gut permeability, together with gut toxins in the bloodstream, could be a factor for some people with acne.

Acne is not the only skin condition to have been considered. An imbalance of gut microbes is ten times more common in people who have rosacea, according to another study. Treatment of this imbalance, using antibiotics, led to an improvement in rosacea symptoms in the majority of patients in the study, and these improvements lasted several months.

A further study showed that infants who developed eczema before they turned one had a less diverse collection of gut bacteria during their first month of life than infants without eczema, suggesting a link between gut bacteria early in life and the development of the skin condition.

Remind me, what are probiotics?

Probiotics are good bacteria and the theory is that they improve the balance of different microbes in the gut.

The predominant bacteria in the gut are Lactobacillus and Bifidobacterium, and they are also the most common bacteria in probiotic supplements and food.  Both Lactobacillus and Bifidobacterium produce lactic acid. This helps helps create an acidic environment in the gut which deters many harmful microbes. Lactic acid also provides energy to the cells that line the gut wall which enhances its protective barrier.

Popular probiotic foods include live yogurt, apple cider vinegar, kefir (a fermented dairy drink), miso soup, fermented vegetables (such as sauerkraut and kimchi) and kombucha (fermented black tea).

Can consuming probiotics improve skin?

The first formal research on the potential value of probiotics, published in 1961, looked at 300 acne patients who were given probiotic supplements.   Eighty per cent of those with acne experienced some degree of improvement and the study concluded that ‘interactions of skin manifestations of acne vulgaris and of metabolic processes of the intestinal tract are suggestive’. In other words, acne and microbe activity in the gut appear to be linked.

A more recent study, involving 36 patients with acne, showed that drinking lactoferrin-enriched fermented milk could improve acne over a 12 week period (lactoferrin is a milk protein thought to reduce inflammation). The lactoferrin-enriched probiotic led to reductions in spots and a reduction in sebum production, and also altered the composition of skin sebum.

All in all, there is promising evidence for the the use of probiotics in treating acne in combination with other treatments. It is thought that the potential benefits of probiotics could extend across the board of inflammatory skin conditions, which include eczema, psoriasis and rosacea.

How about putting probiotics onto my skin?

Preliminary studies of topical probiotics, that is probiotics applied to the skin, have shown that they may help to reduce the number of pimples and pustules in acne. Lactobacillus has been shown to produce proteins which not only have anti-microbial activity against the bacteria that cause acne spots, but also have direct anti-inflammatory activity.

Researchers have also shown that probiotic bacteria can increase ceramide production when applied to the skin for two weeks. Ceramides form part of the skin’s natural barrier, helping skin to retain moisture.  Ceramides are often added to skin care products to help repair skin barrier damage from environmental factors and the ageing process.  Ceramides are also effective in treating eczema. As such, topical probiotics hold promise as a treatment for several skin conditions.

Do probiotics help with wrinkles?

The use of probiotics in anti-ageing is an exciting new area but needs more research. Given the anti-inflammatory and ceramide-promoting properties of probiotics, it is plausible that they could be of benefit. Some companies are adding probiotic bacteria, or extracts of these bacteria, to their skin care products, but there is no evidence that the bacteria survive in these products or that the extracts are effective.

Early indications are that probiotics are worth the hype. Taken as supplements, eaten as foods or used on skin, probiotics could prove a useful and versatile treatment in combination with other treatments. This area is one to watch.

Products that contain probiotics include Dr Johanna Ward’s ZENii Probiotics