The Silent Infection Load: How Lifelong Asymptomatic Infections May Contribute To Inflammaging As An Evolutionary Trade-Off Of Longevity
We often think of infections as something that makes us visibly sick, but what if “silent” infections, those without obvious symptoms, are quietly impacting our health over the long term? New research suggests that these lifelong, asymptomatic encounters with microbes are far from neutral. While they might seem harmless because our immune system keeps them in check, they actually trigger a continuous, low-level immune response.
This constant immune activation, though subtle, comes with a cost. From an evolutionary perspective, maintaining a diverse array of microbes and a state of immune readiness can be beneficial for long-lived organisms, helping them fight off more severe infections. However, this adaptive advantage is balanced by the ongoing burden of chronic, almost undetectable inflammation, a process now termed “inflammaging.” Inflammaging is a persistent, low-grade inflammation that contributes to the gradual decline of our immune system (immunosenescence) and accelerates the aging process.
Think of it like a tiny, persistent alarm going off in your body. Each individual “alarm” (asymptomatic infection) might be mild, but their cumulative effect over a lifetime can lead to micro-damage, affecting our metabolic and vascular health and contributing to the systemic inflammation characteristic of aging. Even clinically mild or initially asymptomatic infections, such as those seen in “Long COVID,” can leave lasting immunological and metabolic traces, highlighting the long-term consequences of these silent microbial interactions.
Source: link to paper