My PhD research centred on redefining hypertension as a condition shaped by diet–microbiome interactions, immune regulation, and pH‑sensing pathways. By integrating experimental models with human cohort data, I investigated how dietary fibre and its fermentation products influence blood pressure and its complications. A central focus was the role of short‑chain fatty acids and their ability to lower colonic pH. I examined how fibre‑driven shifts in gut acidity activate pH‑sensing receptors such as GPR68, and how this signalling shapes inflammatory pathways relevant to hypertension. This work provides mechanistic insight into how restoring microbial metabolism may help prevent high blood pressure, particularly in the context of Westernised, low‑fibre diets.

I also leveraged the opportunity to analyse human data from the pH of Intestines and Blood‑pressure Regulation (pHibre) clinical trial conducted in our laboratory. Using a unique in vivo motility testing system, which is no longer commercially available, that offered the most comprehensive characterisation of human colonic intraluminal pH to date, I explored real‑time gastrointestinal pH dynamics in relation to blood pressure. My findings revealed the first in‑human evidence that individuals with essential hypertension display distinct intraluminal pH profiles, independent of antihypertensive medication use or blood pressure control. Complementary immune‑profiling within the same cohort identified peripheral immune signatures associated with hypertension, providing a new perspective for biomarker development and personalised monitoring. Together, this body of work reframes hypertension through a systems‑level lens, in which dietary fibre‑derived short-chain fatty acids shape interactions between the gut environment and the immune system. My hope is that this work serves as a step towards identifying new mechanistic entry points for intervention and helps broaden how we think about and approach the management of high blood pressure.