The findings, which was reported recently at the International Society for Hyaluronan Sciences (ISHAS) conference last month, expands our understanding of how oral consumption of Hyaluronic Acid may impact skin health from within.
Working with scientists from Hungkuang and Providence Universities in Taiwan and Kobe University in Japan, the Kewpie scientists reported that bacteria in the large intestine may convert HA to low molecular weight oligosaccharide forms. This finding challenges the previous hypothesis of HA’s mechanism of action, which was that HA was converted by hyaluronidase enzymes in the small intestine.
“This doesn’t alter the evaluation of HA’s effectiveness, but opens an entirely new branch of inquiry into its optimization, one that Kewpie’s researchers have already set out upon,” said Kewpie in a press release.
HA and skin health
HA is found naturally throughout the body, with the highest concentrations in the joints, eyes, and skin. The skin contains about 50% of the body’s hyaluronan (HA), a component present in every connective tissue. Degradation of HA and collagen is reported to be a cause of wrinkles, with many ingredient suppliers exploring the potential of supplementation to improve skin health from within.
Despite the interest in hyaluronan, only a handful of clinical trials investigating the efficacy of oral consumption of HA on skin health parameters are reported in the literature (see PubMed, accessed July 23, 2021).
Scientists from Kewpie authored a review in 2014, published in the Nutrition Journal, which concluded: “The reduction of HA in the skin by intrinsic and extrinsic factors such as aging and ultraviolet radiation, smoking and air pollutants induce dryness in the skin. However, daily HA supplements can moisturize the skin because the metabolites of HA increases the skin moisture content by having an effect on the skin cells. Thus, consuming HA affects skin cell and improves dry skin physiologically.
“This review shows that consuming HA moisturizes the skin and employing HA as a dietary supplement makes the skin healthy. We believe that countries worldwide will benefit from this review and consume HA to alleviate dry skin.”
The researchers used the Kobe University human intestinal microbiota model (KUHIMM) to investigate the degradation of HA by human intestinal bacteria, and liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) and a three-dimensional skin model to assess the absorption of the HA component and its effect on collagen metabolism, respectively.
The data indicated that HA was not digested in the small intestine but “degraded into oligo-HA by intestinal bacteria in the large intestine”.
A spokesperson for the company told NutraIngredients-USA every participant had a bacterium that would degrade HA, but the study was only conducted on 10 people, and “therefore, it was not clear evidence… The degradation efficiency differed depending on its type or number of bacteria the individual had, and 20% (2 people) degraded HA with high efficiency.”
The LC–MS/MS analysis and skin model revealed that a “sizable amount of the degraded oligo-HA was absorbed and reached the skin to promote collagen metabolism, which may have beneficial effects such as wrinkle improvement by upregulating both collagen decomposition (matrix metalloproteinase-1) and synthesis (procollagen) in the dermis,” reported the researchers in their abstract for the conference.
This study was funded by Kewpie Corporation, which makes the Hyabest(S)LF-P brand of HA.