Healthy Skin From Within: Combining Supplemental NMN With Probiotics to Fight UVB-Induced Skin Damage and Aging
From benign wrinkles and age spots to the more malicious skin disorders, our skin takes the brunt of the damage from excessive sun exposure. Despite its myriad benefits, including providing our primary source for vitamin D synthesis and improving mood, the sun also has a dark side to its brightness — UV radiation.
In a recent study published in Frontiers in Pharmacology, a research team out of Chongqing, China, looked at how to fight back on the damage that occurs after UV exposure, using two compounds — NMN (nicotinamide mononucleotide) and lactic acid bacteria (LAB). Briefly, NMN is a precursor to the essential enzyme NAD+, which is needed by every cell in the body and tends to decline with age. Lactic acid bacteria (LAB) is a probiotic — a healthy type of bacteria in the gut — that has been linked to anti-aging, antioxidant, and immune-regulating activity.
Using this combination therapy in mice, Zhou and colleagues show that the detrimental effects of skin aging can be reversed after UVB exposure, providing a starting point for using NMN+LAB supplements to possibly prevent or treat sun-induced skin damage.
The Dark Side of the Sun
As one of the body’s first lines of defense against toxins and foreign invaders, the skin is tough and protective but not immune to the harm caused by ultraviolet rays. UV radiation, especially from UVB rays, is considered the most significant external factor that causes photoaging — the term for premature skin aging due to repeated light exposure. Not only does excess UVB radiation contribute to outward signs of aging (think: wrinkles, lost elasticity, and rough or leathery skin), but it is also linked to a large percentage of the most serious skin diseases.
Although we already have an excellent skin-protecting product called sunscreen, many people still overexpose themselves to UV rays or want to undo some damage from their sun-worshipping past. Interest in anti-aging compounds has never been higher — both from the beauty-focused side, in fighting wrinkles and crow’s feet, and the health-minded side of preventing more serious skin disorders.
Fighting Back on Photoaging
In this study, mice were treated with either a combination of NMN and LAB, NMN or LAB on their own, or vitamin C before UVB damage was induced. As vitamin C is a known antioxidant, the research team used this treatment group to gauge the antioxidant capacities of NMN and LAB.
Before studying the treatments’ effects in the animals, Zhao and colleagues looked at how well these compounds worked as antioxidants in a cell-based study. They found that the NMN+LAB combination exhibited the greatest antioxidant capacity, more so than vitamin C, NMN, or LAB on their own. The combination of NMN and LAB showed a much higher ability to scavenge free radicals — reactive and inflammatory compounds that cause oxidative stress and damage to cells — suggesting that this duo works synergistically to augment their antioxidant activity.
From there, the researchers looked at how these treatments affected oxidative stress and inflammation in the mice. In the UV-damaged group that didn’t receive any supplements, the mice had significantly lower levels of two antioxidant enzymes — catalase and superoxide dismutase — and lower levels of the anti-inflammatory compound interleukin-10 (IL-10). The UVB-damaged mice also had much higher levels of pro-inflammatory compounds and damaging molecules called advanced glycation end-products (AGEs), which would accelerate skin aging.
Both the NMN and the NMN+LAB mice exhibited reversals of these imbalanced antioxidants and inflammatory markers, although the combination group had more beneficial improvements than either group alone. While most of these biomarkers got reversed back to levels of the healthy controls, the NMN+LAB group also experienced an additional boost in the antioxidant superoxide dismutase, reaching levels that were even higher than the healthy mice who didn’t have any UV damage.
These results show that UVB exposure induces severe oxidative stress and inflammatory damage in the skin. While NMN treatment beforehand can mitigate this damage, the combination of NMN and the probiotic LAB seems to work even better. As oxidative stress plays a crucial role in skin photoaging, Zhao and colleagues speculate that the NAD-boosting abilities of NMN and the probiotic capacity of LAB work well together to fight free radical damage and diminish inflammation in the skin.
The Wrinkle-Free Combo of NMN and Probiotic Bacteria
As we know that UV radiation causes external skin aging, Zhao and colleagues next wanted to see if NMN and LAB treatment could prevent or reverse this appearance-related damage by boosting the production of our body’s most abundant protein — collagen. After our mid-20s, our skin produces about 1% less collagen each year, and UVB damage can make this collagen decline occur even more rapidly. Without adequate collagen, skin can become more wrinkled and thin, and less elastic, hydrated, and smooth.
After UVB exposure, the mice had reduced skin thickness, smaller and fractured collagen fibers, and fewer collagen bundles — all of which are expected symptoms after sun damage. While the NMN, LAB, and vitamin C groups did have increased skin thickness, they did not improve their collagen structures and adhesion — only the NMN+LAB group exhibited enhanced collagen quantity and quality.
Mitigating collagen loss with age could dramatically improve the skin’s external appearance, allowing for increased elasticity and hydration with fewer wrinkles. The NMN+LAB mice also had fewer mast cells — an immune cell that triggers rapid inflammatory responses — indicating that this combination treatment significantly reduces skin inflammation after UVB exposure.
Lastly, Zhao and colleagues looked at how NMN and LAB affected cellular energy production. While UVB exposure caused a marked drop in NAD+ levels in the skin, the NMN+LAB treatment significantly boosted NAD+ levels back to that of the healthy mice. Plus, the NMN- and LAB-treated mice showed higher activity of AMPK — a so-called longevity enzyme that acts as a master metabolic regulator in the body. Elevated AMPK can promote SIRT1 activity, a protein linked to longer lifespan, reduced oxidative stress, and efficient cellular energy production.
Skin-Supporting Supplements, From the Inside Out
Although we have seen in previous research that supporting healthy NAD+ levels through supplemental NMN improves heart, kidney, brain, and liver health in animals, studies haven’t yet shown how this NAD-booster affects the skin — and we have not yet seen how NMN interacts with probiotics like lactic acid bacteria. In this study, Zhao and colleagues found that the combination of NMN and LAB produced greater beneficial effects to the skin, both in external appearance and with internal biomarkers, than either compound alone.
Zhao and colleagues speculate that LAB bolsters NMN’s beneficial effects because some studies have found certain bacteria to help NMN convert into NAD+. As the authors state, “This research may indicate that the [bacteria] in our study played a role in improving skin injury by promoting the synthesis of NMN into NAD+.” Although this study was not done with humans, it provides a jumping-off point for how NAD-boosters and probiotics can work in tandem to improve skin health after UV damage. Even when taken internally, rather than used topically, this combination of NMN and lactic acid bacteria shows promise for fighting skin aging, from the inside out.
Shats I, Williams JG, Liu J, et al. Bacteria Boost Mammalian Host NAD Metabolism by Engaging the Deamidated Biosynthesis Pathway. Cell Metab. 2020;31(3):564-579.e7. doi:10.1016/j.cmet.2020.02.001
Zhou X, Du HH, Ni L, et al. Nicotinamide Mononucleotide Combined With Lactobacillus fermentum TKSN041 Reduces the Photoaging Damage in Murine Skin by Activating AMPK Signaling Pathway. Front Pharmacol. 2021;12:643089. Published 2021 Mar 25. doi:10.3389/fphar.2021.643089