Fig 2: Ketogenic diet induces relative corticosterone deficiency in C26-tumor bearing mice.(A) Corticosterone hormone levels in plasma of cachectic C26 tumor-bearing mice and littermate controls fed KD or NF diets (n=5 LM, n=10-14 C26). (B-C) Plasma cholesterol levels in cachectic C26-tumor bearing mice and littermate controls (n=5 LM, n=10-11 C26) (B), and in cachectic KPC tumor-bearing mice and PC controls (n=5-8) (C) fed KD or NF diet. (D) Pregnenolone hormone levels in plasma of cachectic C26 tumor-bearing mice and littermate controls on KD or NF diets (n=16-22). (E) Sodium levels in plasma of cachectic C26-tumor bearing mice and littermate controls on KD or NF diets (n=5 LM, n=10-11 C26). (F) Levels of adrenocorticotropic hormone (ACTH) in plasma of cachectic C26 tumor-bearing mice and littermate controls fed KD or NF (n=6-10 LM, n=12-20 C26). (G-H) Synacthen test and quantification of corticosterone response at baseline and 15, 30 and 60 minutes after ACTH stimulation in cachectic C26 tumor-bearing mice and littermate controls (endpoint) (G), or only 4 days after diet change (18 days after C26 cell injection) (n=5) (H).Data are expressed as the mean ± SEM. One-way ANOVA with Tukey’s correction for post hoc testing was used in (A-D, F). Two-way ANOVA statistical tests with Tukey’s correction for post hoc comparisons were performed in (G-H). * p-value < 0.05, ** p-value < 0.01, *** p-value < 0.001, **** p-value < 0.0001, # p-value < 0.05 compared to time = 0.

Fig 3: Reserpine-induced changes in serum levels of HPA-axis hormones. A The model group showed increased ACTH level. B The model group showed increased CORT level. Data is expressed as the mean ± SD. ***p < 0.005, compared with their respective control group

Fig 4: The effects of antibiotic treatment alone or in combination with Aß1–42 treatment on HPA axis function (A ACTH; B corticosterone) and brain oxytocin (C) in male C57BL6 mice. Data are expressed as mean ± SEM (n = 10). Antibiotic treatment significantly increased brain oxytocin [p = 0.013] but did not alter [p > 0.05] ACTH and corticosterone levels in the serum of mice as compared to the water + vehicle group. In addition, Aß 1–42 administration significantly increased ACTH [p = 0.012] and corticosterone levels [p = 0.049] but not brain oxytocin [p > 0.05] in water-treated mice as compared to the water + vehicle group. Furthermore, no significant differences [p > 0.05] in ACTH, corticosterone, and oxytocin levels were observed between antibiotics + Aß 1–42 mice and antibiotics + vehicle or water + vehicle groups.

Fig 5: MRbR mice developed ACTH-secreting PitNETs.(A) H & E, IHC staining for prolactin, growth hormone, and ACTH on pituitary sections in MRb, MRbR, and RbR mice. Anterior lobe (A), Intermediate lobe (I), and Posterior lobe (P) of normal pituitary in MRb mice are shown in the H & E section. (B) Serum ACTH levels using ELISA assays in MRb, MRbR, and RbR mice confirmed that the PitNETs from MRbR and RbR mice were ACTH-secreting tumors. Serum ACTH levels between MRbR and RbR mice were not significantly different (p = 0.0581), but were significantly higher than that in MRb mice of the same age and sex as that of MRbR mice (p < 0.0013). (C and D) No gender bias was observed in MRbR and RbR mice for survival or pituitary growth as they age. (C) Survival curve. The survival curves of MRbR (p = 0.6612) and RbR (p = 0.7535) mice showed no statistical significances between female and male mice. (D) Pituitary growth.