In this document, two of the latest results obtained by the LHCb Collaboration on the area of charmless $b$ decays are summarised. The first observation of the very rare $B^0\rightarrow K^+K^-$ decay mode is presented, together with the most precise measurements of $ \mathcal{B}(B^0\rightarrow K^+K^-)$ and $\mathcal{B}(B^0_s\rightarrow \pi^+\pi^-)$. The second result is related to $CP$ violation in baryonic matter. A search for $P$ and $CP$ violation was performed by studying triple-product asymmetries in the $\Lambda^0_b\rightarrow p\pi^-\pi^+\pi^-$ and $\Lambda^0_b\rightarrow p\pi^-K^+K^-$ decay channels. This leads to the first evidence of matter-antimatter asymmetry in the baryonic sector.