Recently, a subtype of obesity characterized as a metabolically healthy but obese (MHO) individual has been identified. However, limited data are available on these MHO individuals’ metabolic and inflammatory profiles, and the effect of weight loss on these profiles. We investigated metabolic and inflammatory markers in MHO women to determine the effects of a 12-week weight loss on those markers. One hundred and twenty-nine overweight-obese Korean women participated for 12 weeks in a clinical intervention study involving a 300 kcal/day intake reduction. The subjects were divided into two groups: MHO and metabolically abnormal obese (MAO) individuals. Computed tomography was performed. C-reactive protein (CRP), interkeukin-6 (IL-6) and oxidized low-density lipoprotein (LDL), as well as blood lipids, glucose and insulin concentrations were determined at baseline and after weight loss. At baseline, plasma CRP (P<0.001), IL-6 (P<0.05) and oxidized LDL (P<0.001) levels were significantly lower in the MHO group than in the MAO group. Visceral fat at L1 (P<0.005) and visceral fat at L4 (P<0.001) were significantly lower in the MHO group than in the MAO group. The treatment induced weight loss averaging 3.11% of initial body weight, and the degree of weight loss between the two groups was similar. Visceral fat at L1 and L4 was reduced from its initial values by 3.2 and 5.4%, respectively, after weight loss. The levels of CRP (P<0.05) and oxidized LDL (P<0.01) were significantly reduced in the MAO group after the 12-week weight loss, whereas these effects were not seen in the MHO group. Our results showed that MHO individuals exhibited lower visceral fat accumulation and more favorable metabolic and inflammatory states than MAO individuals. After a 12-week weight loss program, significant reductions in blood lipids, CRP and oxidized LDL levels were observed in MAO individuals. However, there was no measurable effect of weight loss on lipid profiles and inflammation in MHO individuals, indicating differing effects of weight loss on these markers between MAO and MHO groups.

Inappropriate interleukin-6 production is thought to play a role in the development of several age-related conditions including atherosclerosis. This study aimed to determine whether aging affects circulating interleukin-6 (IL-6) levels. Healthy, nonobese women (n = 208, 44.5 ± 0.70 years, 22.4 ± 0.17 kg/m²) were categorized into four age groups (22–31, 32–41, 42–51, and 52–63 years; cross-sectional study). Cytokine levels in serum and those produced from peripheral blood mononuclear cell (PBMC) were measured. The oldest group had the highest circulating levels of IL-6 and oxidized low-density lipoprotein (ox-LDL) and higher PBMC production of IL-6, tumor necrosis factor-α (TNF-α), and interleukin-1 alpha (IL-1β). Additionally, significant interactions between age and menopause were found for serum IL-6 (P = 0.024), and TNF-α (P = 0.011) and IL-1β (P < 0.001) produced from PBMCs. Serum IL-6 levels positively correlated with age, waist–hip ratio (WHR), systolic blood pressure, circulating levels of TNF-α, IL-1β, and ox-LDL, and urinary 8-epi-prostaglandin F₂α. Multiple stepwise regression models identified the following factors for contributing to serum IL-6 levels: serum IL-1β, menopause status, WHR, and serum TNF-α in mode I (R ² = 0.302); serum IL-1β, age, serum TNF-α, and WHR (β = 0.197; P = 0.006) in model II (R ² = 0.283). Sub-analysis was performed according to menopausal status. Serum IL-6 levels were positively associated with levels of IL-6, TNF-α, and IL-1β in PBMC supernatants (unstimulated) from postmenopausal women, whereas these were negatively associated in premenopausal women. In conclusion, circulating IL-6 levels may be interactively influenced by age and menopause. Additionally, estrogen deprivation after menopause may enhance PBMC cytokine production in postmenopausal women, resulting in increased IL-6 levels which are closely related to oxidative stress.

The aim of this study was to investigate the impact of consuming dairy yogurt containing Lactobacillus paracasei ssp. paracasei (L. paracasei), Bifidobacterium animalis ssp. lactis (B. lactis) and heat-treated Lactobacillus plantarum (L. plantarum) on immune function. A randomized, open-label, placebo-controlled study was conducted on 200 nondiabetic subjects. Over a twelve-week period, the test group consumed dairy yogurt containing probiotics each day, whereas the placebo group consumed milk. Natural killer (NK) cell activity, interleukin (IL)-12 and immunoglobulin (Ig) G1 levels were significantly increased in the test group at twelve weeks compared to baseline. Additionally, the test group had significantly greater increases in serum NK cell activity and interferon (IFN)-γ and IgG1 than placebo group. Daily consumption of dairy yogurt containing L. paracasei, B. lactis and heat-treated L. plantarum could be an effective option to improve immune function by enhancing NK cell function and IFN-γ concentration (ClinicalTrials.gov: NCT03051425).

In vitro and animal studies have demonstrated that Chlorella is a potent biological response modifier on immunity. However, there were no direct evidences for the effect of Chlorella supplementation on immune/inflammation response in healthy humans.