Diet is one of the factors that can influence gene activity. A small pilot study from the University of Helsinki measured, for the first time using RNA sequencing, which genes in the skin of dogs were differently active following a dietary intervention with raw food versus kibble. The findings are exploratory.
Food that aligns with the biology of the dog
Raw proteins and fats, no ultra-processed carbohydrates
Genes and diet: what is the relationship?
Every organ depends, for its function, on which genes are active. Diet is one of the factors that can determine which genes are switched on or off, alongside genetics, environment, and age. Earlier studies in mice, rats, and humans showed that dietary changes can lead to measurable shifts in gene expression. In dogs, this had never been investigated for the skin using RNA sequencing.
It is important to emphasise that changes in gene expression are not evidence of better skin health or a stronger immune defence. They indicate that certain biological pathways are differently active. The clinical significance of those shifts requires separate research.
The study: Staffordshire Bull Terriers, kibble versus raw
Anturaniemi et al. (2020) divided eight Staffordshire Bull Terriers into two groups: four dogs received a commercial kibble diet (high in carbohydrates, low in fat) and four dogs received a commercial raw meat diet (high in fat, low in carbohydrates). Within each group, two dogs were atopic and two were healthy. The intervention lasted 84 to 147 days.
Skin biopsies were taken before and after the intervention and analysed using RNA sequencing. Both diets differed in two respects at once: the degree of processing and the macronutrient ratio. As a result, it cannot be determined which of these factors caused the gene expression differences found.
Anturaniemi et al., 2020 |
Frontiers in Veterinary Science, 7:552251 — First RNA-seq study into the effect of diet type on gene expression in the skin of dogs. n=8 dogs (pilot). DOI: 10.3389/fvets.2020.552251 |
Which genes differed between the diet groups?
In the raw-fed dogs, 33 transcripts were activated differently after the intervention compared to the kibble-fed dogs. Eight of these transcripts are annotated in the dog genome. All eight were more highly activated in the raw-fed group. The study measured only RNA expression, not clinical improvement in skin health or atopy.
IGHM, IGLL5, and CD79B are involved in B-cells and adaptive immunity. Higher expression is associated with pathways for immunoglobulin production and lymphocyte proliferation.
PIGR is a transport protein for immunoglobulins to the mucosal surface and is linked to barrier functions of epithelial tissue. The functional significance for the dog in this context has not been established.
SLPI was more highly activated in the raw-fed dogs. In earlier studies of atopic dogs, SLPI was actually lower. The higher expression in this study may be relevant, but the study does not show a proven strengthening of the skin barrier.
CBS and ASS1 are involved in glutathione-related metabolic pathways. The study did not measure oxidative stress in the dogs; conclusions about stress reduction cannot be drawn from this.
MRRF plays a role in mitochondrial ribosome recycling. The functional significance of higher expression in the skin context remains uncertain.
The study measured only RNA expression in a small number of dogs. Transcription changes are an interesting indication, but not proof of better skin health, stronger immune defence, or reduced atopy. The clinical relevance of the shifts found is unknown.
Scientifically honest
This is a pilot study with only eight dogs, four of which were atopic. The small sample limits the statistical power. The diets differed simultaneously in processing and macronutrient ratio, meaning the cause of the gene expression differences cannot be established. The study was not blinded and the dogs lived in their home environment, meaning other factors have not been ruled out. Larger, better-controlled studies with clinical endpoints are needed for interpretable conclusions.
Wolfork and the researched dietary profile
The raw diet in the study was unprocessed, high in animal proteins and fats, and low in carbohydrates. Wolfork has a comparable nutritional profile. Based on this study, it cannot be concluded that Wolfork brings about the same gene expression changes as the diet in the study, or that Wolfork improves skin health.
The findings are interesting as an exploration of how diet can influence the skin at the molecular level. They justify follow-up research with larger numbers of dogs and clinical endpoints.
What this means in practice
In this pilot study, differences in gene expression in the skin were found between dogs on a raw diet and dogs on kibble. All eight annotated genes were more highly active in the raw-fed group, and are involved in pathways for immunity and metabolism. The study measured only RNA expression, not clinical improvement in skin health or atopy. The small study size and the simultaneous difference in processing and macronutrients make causal conclusions impossible. Follow-up research with larger numbers and clinical endpoints is needed.
Raw food with a nutritional profile comparable to the study
Unprocessed, high in animal proteins and fats
Source
Anturaniemi, J. et al. (2020). The Effect of Atopic Dermatitis and Diet on the Skin Transcriptome in Staffordshire Bull Terriers. Frontiers in Veterinary Science, 7:552251. DOI: 10.3389/fvets.2020.552251
Comments (0)
There are no comments for this article. Be the first one to leave a message!