Adipose-derived stem cells remember obesity – anti-inflammatory capacity restored only years after weight loss

In medically indicated weight loss, attention is typically focused on the associated health benefits. However, recent research findings suggest that recovery from obesity-induced systemic inflammation may take several years.

Amna Adnan’s new study sheds light on how weight loss influences the functional characteristics of adipose stem cells at the cellular level. She examined adipose-derived stem cells harvested from the same donor before and after bariatric surgery and subsequent weight loss.

Bariatric surgery involves reducing or bypassing the stomach to limit food intake, with the aim of achieving weight loss and alleviating obesity-related conditions such as type 2 diabetes and cardiovascular disease.

Adipose stem cells are an efficient form of regenerative therapies. Their properties facilitate tissue repair, suppress immune rejection in grafts and promote the regeneration of tissues. Their therapeutic potential is being explored in the treatment of osteoarthritis, cardiovascular diseases, chronic wounds and Crohn’s disease.

Adipose stem cells can be harvested, among other things, via liposuction with minimal risk to the donor. However, donor-specific factors – such as body mass index and weight loss history – affect their suitability for stem cell-based therapies.

Previous studies have shown that obesity impairs the anti-inflammatory functions of adipose stem cells. Adnan hypothesised that these functions would be restored following weight loss, but the findings did not support this assumption.

The analysis of tissue biopsies and plasma samples revealed a reduction in systemic inflammation after weight loss. However, the regulatory mechanisms governing inflammatory responses in adipose stem cells had not returned to baseline at the cellular level.

“These results have reshaped our understanding of adipose stem cell behaviour following weight loss. Even though bariatric surgery improves general health, the functional recovery of adipose stem cells remains incomplete even two to three years after the intervention. This means that individuals who have undergone significant weight loss may not be suitable donors for cell therapies aimed at suppressing inflammatory responses,” Adnan explains. 

Led by Professor Susanna Miettinen, the Adult Stem Cell Group is developing a tissue culture model derived from adipose tissue. The aim is to investigate the functional differences between healthy and diseased adipose tissue, and to support drug testing and the advancement of personalised medicine. In an upcoming research project, adipose-derived stem cells and vascular endothelial cells will be cultured on a three-dimensional tissue chip to study their angiogenic potential. The study will utilise stem cells obtained from donors with normal weight, overweight and morbid obesity. The first results are expected in autumn 2026.

The article Effects of Bariatric Surgery-Related Weight Loss on the Characteristics, Metabolism, and Immunomodulation of Adipose Stromal/Stem Cells in a Follow-Up Study was published in Stem Cells International on 13 May 2025.

Watch a short video explaining how weight loss affects adipose stromal stem cells: New insights into how weight loss affects adipose stromal stem cells